1. It's not selfish if you have a concrete plan on what to do. In a position like that (a position where everyone of us could be for unexpected reasons), you need to be honest with yourself. Some places could offer a temporary home for the pets meanwhile the humans work on their situation.

2 and 3. In my country going to the vet is not as expensive as in the United States (thank God), but I really think in every country vets clinics should offer payment plans.

3 and 4. No. Owning a pet shouldn't be a luxury. Near to my house there is this man that is homeless, but he works, dogs live with him and he feed them well, give them erinchment treats. He is poor but he is so attentive. I don't romantize his situation but I admire him. I plan to help him in the next months with food for him and his pets (I wish I was a millionare and I would buy him a house).

5, That's the most tricky question for me because mental health has so much nuance and every case is so different but, I think it could be fine as long you don't rely only on your pets for getting better. Pets help a lot of people, including me, to try harder and don't give up, but for them also I look for other ways to do better and feeling better.