I really need some advice about what to do with my dog. I rescued him in January (he's a six year old black lab mix), and things have been going well for the most part. My roommate at the time I adopted him had two cats, one of whom he really bonded with, and he settled in pretty easily. My roommate moved in with her boyfriend in April, and I found a new roommate who also had a dog. I thought it would be great for him because his foster family said he loved their dog and got along well with the other dogs at the shelter they got him from. My new roommate's dog is basically terrorizing him when they're together (biting his face, humping him, chasing him, etc.), though, so we generally keep them separated unless they can be supervised.

My dog is terrified of his crate, so much so that I can barely get him in it. With my previous roommate he was given free reign around the house with the cats while we were at work and had no problems, so the crate was never needed. My new roommate opted to crate her dog while we're at work, so she's been using my crate and I've been leaving my dog out to roam. Without the cat, or any other animal, to play/hang out with during the day he's been getting restless and eating things. So far he's chewed a pair of Coach flip flops, my duvet, a blanket, a pillow, my roommate's couch, and assorted paper products. I've tried bones, toys, etc. to get him to stop, but nothing is holding his interest. It also doesn't help that in the evenings he's mostly stuck in my room while my roommate's dog is out roaming the rest of the house.

I generally keep him pretty active. We don't have a fenced in yard, or any sort of yard, but we live on a biking/running trail that I walk him on. We typically walk for 10-15 minutes in the morning and 15-20 minutes after work. On the weekends I typically take him for a 4+ mile hike at the local park. He's been through obedience training and is an older dog, so I'm not sure if that's the path I should take. I'm really hoping to avoid having to move (to find a place with a yard or live alone so I can adopt a second animal that he will mesh well with) or shell out $100 a week for doggie daycare that I cannot afford, but I think he's just so unhappy with the current situation and I can't keep having him destroying my stuff.

Does anyone have any experience with this, or any suggestions I could try?

ETA: Wheldon just wanted to say thank you to everyone for all of the great suggestions, and he's really going to try to stop destroying mommy's things.

Calling all canine experts...