Thank you for your responses! :D
I completely forgot to mention- he's not getting a lot of physical exercise. He was neutered not that long ago and is still recovering from the surgery. I completely understand a lack of exercise is part of my problem and he might change when I finally get to wear him out, but it's still a little hard to keep that in perspective...
Today, I continued trying to ignore/leave him when he bites... whenever I returned to play, I generally got met with more biting and barking. Using food to reward him when we're playing and he isn't biting me really seemed to help prevent him from biting me in the first place.
He's also suddenly significantly less behaved when we sit in my room... Something's making him more excitable in my room and it's not clear what. He either barks out the window at nothing (I THINK it's because he knows there are other dogs outside, but he can't even see them or hear them...) or he barks at me and nips me when I sit on my bed (even if I'm paying attention to him and talking to him). I don't get it; neither of these things set him off before. :?:
.Middy.- Do you have suggestions for physical exercise he can do that wouldn't upset his stitches? And how can I teach him basic commands if he's hardly willing to listen to me? :c (P.S., your dog is beautiful!)
RWBY Rose- When you say "redirecting to chew toys", what exactly do you mean? Do you mean just waving them around/ putting them in her mouth? I tried that and he'd immediately drop the toy and go back to biting me... :c
Cardinal- He hasn't been anywhere new, he just takes potty breaks in the front yard. A lot of people let their dogs and cats roam around off-leash in this neighborhood, and since he goes outside frequently, we inevitably meet a lot of friendly neighbors who want to introduce themselves to him. We can't go in the backyard because then he gets distracted by the dogs on the opposite side of the fence and ends up barking and not pottying. I don't actually try to get him to meet anyone new, it just... happens. Sorry, I should have been more specific about that in the first place. :<
I did come across snuffle mats yesterday, I don't exactly have the tools to make one ATM but will make one if I can find what I need. And he hates his crate, even with toys, water, and a nice cozy blanket. His barking is more tearful and anxious when he's in the crate. I DO have a small area that I could try baby-gating off... assuming he doesn't tear the gates down...
Imzadi83- I'm not sure if the shelter would let me change him from an adoption to a foster, but I'll call and ask tomorrow. Will also go looking for rescue groups who are interested in mutts with unknown origins; we're close enough to a big city that I can probably find SOMETHING.
I don't have trainer/behaviorist money, honestly. I just didn't think it was a necessary part of the budget. Like I said, we've never had these kinds of problems before, so we weren't really expecting them... :(
He does actually like the puzzle toy, but he becomes so distressed when anyone leaves that he drops his toys and starts barking. I can try taking him for a short walk once he's fully recovered from the surgery and see how he feels about being left alone then...
The last paragraph was particularly helpful, so thank you. I started exercise and bike riding to cope with my loss a while ago, but I stopped doing both to care for this new dog and didn't even think about the fact that not doing either of those things is probably making me even more stressed. I'll try doing something relaxing before I wake Jake up tomorrow morning. c:
Sorry for my extremely long posts, I don't know how to paraphrase for the life of me. @_@