Hello Nothing Left, in one way or another I join Jonjr and Lambent in being in the same position as you, and no it's certainly not pleasant and feel very sorry this has happened.
I know missing your pets is devastating and wonder if being in a flat you are allowed to have a pet, I live in a 2 bedroom flat and allowed to have my dog, otherwise I wouldn't be here.
If you can, there are many ways to purchase an animal, and you can have a puppy, then you can take it to puppy school training, there you can meet other people, all with loveable pups.
My two sons didn't want much to do with me, but after a while I kept on trying to contact them, one son was much easier than the other and finally, now both of them are very close to me, with one being my carer and because your both your sons aren't talking to you, you can try and persevere with them, depending on what's happened.
You can, if you want to connect with the 'Mens Shed' who have people who have been in the most awkward positions, you can talk to.
If this was suggested to me I probably wouldn't have done anything, but instead, I was able to build up my confidence and every one has a different way of doing this and may be puppy school may do this, and there are people like me who wants someone to walk my dog for me, every day, second or third day.
We are all with you, every step of the way, and talk with us, you have friends here that have been through what you are dealing with, and sincerely want to help you.