River Runs Through It- What Do?

My dog's name is River, a double homage/ nerd entendre referencing two of my favorite female fictional characters, River Song from Doctor Who and River Tam from Firefly. She's friggin' adorable. Observe, a progression in cuteness:

Looking kind of noble, but bored here, right? 

 Aw, see, friggin' cute!

 But this is definitely the best.

Totally my dog. She loves that Batman blanket. And peanut butter*. A dog after my own heart. She's a pit mix of some sort, although what else with, not sure. Three years old (ish) (the vet we've taken to her thus far is entirely incompetent, so when I change vets, I'll tell you if they give me a different age). It was obvious she came from a loving home, as she had no signs of abuse or neglect, was in perfect physical condition, and was house trained and knew a bunch of indoor tricks- she can sit, shake, lay down, stay, come, and jump. But her outdoor behavior seems to have gone completely unchecked- she tugs like crazy on the leash, sniffs every single blade of grass, and gets aggressive when other people or dogs are in her line of sight. Also, she jumps when people first come into the apartment and gets really hyper for a while.

My roommate was out of town all week for spring break, so it was just River and me. She bolted out the door on Tuesday as I was taking the recycling out (and before accusations are flung, I had barely opened the door when she shoved past me- I had planned on yanking the bin, which I had brought over with me, outside and slamming the door shut really fast; in other words, it isn't like I had left the door hanging open), but it didn't go too badly- she ran around the complex a bit and chased some teenager to his door; since the door was in a covered archway, she boxed herself in, so I snatched her pretty fast and took her home.

I looked this up online, and realized while I hadn't handled it the best, I also didn't do too terribly. I just stayed silent and took her home and threw her in the cage she goes in when nobody's home for a while (which is better than yelling when I got her back, although not as good as giving lots of praise as soon as she was in my possession again). It did freak me out though, and I decided I should probably get a dish for treats to put next to the door so that I or anyone else could grab some to go after her with. But I didn't actually get the chance to do it before last night. AND LAST NIGHT WAS AWFUL. I had friends over, and as some were leaving, I said I was going to take River out, but could they wait so I could get a bag for any droppings. They didn't hear me say this, so they opened the door and let it hang there. And River? She bolted. And this time, as I and one of the people that had been leaving followed, she crossed the street and started running in a patch of houses. After a block or so, I was so distraught that I collapsed and started sobbing. The friend had been ahead of me, so they turned and helped me up, but I was so upset, I just slapped their chest a few times and screamed, "I TOLD YOU TO WAIT!"

"I'm sorry! I didn't see her, and I thought you were right behind us." I said it didn't matter, we needed to find her, I didn't see which way she went, let's split up. So we went in opposite directions, but a few moments later, I heard them holler my name instead of River's. I turned around and ran full force in that direction, and like an angel holding redemption itself, there this friend was, carrying my River toward me. It was like a movie as the two of them emerged into the halo of a streetlight, I swear. The friend said she had just flopped down in the grass of someone's front lawn and wagged her tail like mad as they approached her. I gave her lots of praise once we were at the door, but I didn't stop crying for longer than I let on with my friends (and cried harder as soon as they were gone); I was shaking for about half an hour (I had to call someone that usually is able to get me to relax, even without realizing it- thank God for this person). I slept like crap, too.

So then today, my roommate got home and accidentally got a boot she was carrying stuck in the door. So of course, River bolted again. I had no shoes on, and my roommate dropped some stuff on the ground outside our door to chase after River, so after my feet started hurting, I backtracked, put my roommate's things inside, got some Beggin' Strips, River's leash, and my phone, put on some shoes, and ran back outside. I followed the route she had taken last night and saw no traces of her, so as my chest started to hurt (and not from the running), I took the long way back to my place and got there just as my roommate called to tell me the two of them were inside. River had ran over half a mile and trapped herself in someone's yard or something (can't quite remember, I just know she did something similar to what she did when I was alone and went into something with barriers), and then apparently kept trying to lie down on the way back. 

This running-like-lightning-through-the-door thing, I have no idea what to do about it. I have a pretty big apartment, but I need a longer leash to do the right kind of training to get this out of her (which would involve really intense training for "come" and multiple distances and lengths of time, as well as positions). I have a Gentle Leader and all, and I was going to use it to get her to walk better outside (as in stop the fucking tugging on the leash), but I don't know how using that would help me train her to not run away, unless I plan training sessions with other people and have them open the door while she's wearing it and her leash. I'm not trying to make excuses, because I do plan on gettkng the longer leash and figuring out some sort of training regime my roommate and I can execute. I'm just scared out of my mind now that my little baby will run again, and that next time, she won't be found.

Yes, she's microchipped and has all sorts of tags and stuff, but still. I'm positive her previous owner(s) lost her because she bolted and they couldn't get her back; she hadn't been microchipped before, so I imagine they either didn't realize she was gone because they weren't home when she got out, or they lost track of her like I had last night and, for some reason or another, never found her again. So yeah, I do think that, even if her collar somehoe comes off, I'd still get her back. But. I feel like a terrible mother. Three times in less than a week, two in under twenty-four hours. I just feel awful. And really helpless. I want my River to be safe and happy. And I don't want to have to "discipline" her- I have both feet firmly in the school of positive reinforcement, so I'd rather reward her for good behavior than yell at her for bad (and I refuse to strike her, sorry folks).

I wish our spring break was two weeks- I'd take the next week to train her fifteen minutes every hour or two every day. But I go back to school tomorrow, so I guess a few times every evening, and as much as I can on weekends will have to suffice.

*When she eats peanut butter, it's out of one of those Kong things. It's hilarious and adorable, because she doesn't pin it down with a paw, she follows it as it turns around- so she walks in circles as she tries to lick the peanut butter out of it as it rotates, and I've seen her get dizzy a few times doing it. Tee hee!