Ooh that sounds tough, OP. It's awful having nasty neighbours and all you can realistically do sometimes is to keep your head down and avoid them as much as possible.
I love nature, especially birds, but I don't know if you can access any nice outdoor areas where you live?? Would it be possible to have a bird feeder so you can watch them - I could do that all day if I had nothing else to do!
I also enjoy listening to music and reading, which are things you can do in your own space. I enjoy trying to create the perfect cast of actors for any book I've read - it's like a game and it might take some time to get it right to your satisfaction!
Something I enjoy is keeping scrapbooks of news events and things I've done. I was inspired by a lecture about scrapbooks kept by a schoolgirl during the war in which she combined a sort of personal diary with recording events in the wider world and stuck in all sorts of leaflets, adverts, pictures, newspaper cuttings, pressed flowers, drawings etc. It's fascinating to look back on and you can actually make the scrapbook as attractive as you like. It might sound childish, but you're making a record for posterity!
On a more ambitious level - could you start a blog on some topic of interest to you? The quality of blogs varies enormously, so don't feel it has to be a masterpiece. Just walks you've been on, places you've visited, thoughts and interests you have etc. A friend writes about interesting historical London pubs, for eg, and I do one on the local waterfowl on a nearby lake, which sounds crazy but I've had a lot of positive feedback!!! I think for a basic blog you can find info online about starting and it becomes really absorbing and takes you to another place. And you'll get others interested too.
Good luck, OP, and I really hope things get better for you soon. Of course, there's TV and other media - loads of good things available to take you somewhere else for a while.