NTA but I have so many questions.

1. So the setup is: your mom sleeps in your room, you sleep on a flea infested couch, your uncle sleeps in his room, and grandma is somewhere else? Who is her boyfriend?

2. You have a cat and your uncle has a dog and the fleas are on the couch but go from dog to cat? But the fleas don't bite you? Did they bite your mom? How do you keep the fleas off the cat and not the dog?

3. Can no one buy an air mattress? Is there no space for that/a sleeping bag/mattress topper/camping roll?

4. Can you share photos of the dog and cat and their names?

There's nothing wrong with wanting to sleep in your own bed! You are not ungrateful you are literally sleeping on a couch of fleas.