You're not alone, I'm sitting here eating candy instead of getting ready for bed. My rule is no electronics and no food after nine. So I break the rule every once in a while..
My exercise is lifting the remote and changing the channels on days that I don't have to go into the office. You have a fellow couch potato in the struggle with you my friend. I joined a gym in early November, I stopped going by the end of the month. I was extremely lucky that they let me out of my contract.
When I lived in my studio apartment, my cat drove me so crazy that I started looking up shelters to take her to. At the end of the day it was because the space was so small that she got on my nerves. I'm so glad I didn't, but she can still be a pain sometimes.
There are times when I'm super into practicing my Buddhist faith by studying and going to all events. Then there are months in between before I rejoin in group activities.
I'll make plans to be social with friends only to cancel as the day approaches. They stopped asking..
Life can be overwhelming and can maybe cause us isolate out of shame. I think I posted this in the check in thread....I would rather be alone, but I'm sad because I am alone. It's like the "I eat because I'm sad and I'm sad because I eat" catch 22 situations.
Please don't give up on yourself. Living with instability can be a b**** but I feel like I learn more about myself with all the crazy issues I have. But your instability is not your identity. People always ask me what are my hobbies....there is not one hobby that I can say I love to do. I watch tv when I don't have anything to do, which is often. But outside of laying on the couch all weekend I enjoy reading and journaling when the mood strikes me. Are there any particular interests or curiosities you have? Maybe you can explore those. Before I went back to school, psychology was interesting to me based on personal experiences and I started reading up on that subject. I also hate cleaning. But I find that when I throw some music on, it really isn't all that bad and it keeps me moving around instead of laying around. I will also try and do some yard work since both the front and back yards are hideous. I'm being cheap because I know I can do it, but at the same time I'd rather pay someone else to do it.
I'm not sure if any of this is helpful or makes sense, but I just want to let you know that you shouldn't beat yourself up. One of my favorite sayings is "winter always turns into spring" meaning as diffcult as life is and as bleak as you think your future may be, spring will come and new life is born. It gets better so please stay patient with yourself. Try not to focus on the negatives and think about some of the positives. In PHP they had us write lists of what we're grateful for. Start small with one good thing that youre grateful for. Even if it is as simple as I saved 15% or more by switching to Geico! But seriously I hope you are able to get some perspective from the little things.
OK I've rambled on long enough, hopefully it made sense. My thoughts seem to be a little disorganized these days. Please be kind to yourself and take care.

Send me a pm if you ever need someone to vent to..