My cat is very stressed!

 My cat is being bullied by the nieghbors cat so she is becoming very stressed. she has been going poo in her cat tree, I think she's losing weight, and she has become nervous. I need help. how do I get my cat to be less stressed?

Is it possible for you to make your cat an indoor-only cat, at least for awhile?  That's the only way she will feel safe. There are also motion activated sprinklers you can get to keep the other cat away from your house, but that wouldnt be good if your cat was out there.

My parents wont let her be inside unless I have my eyes on her the whole time. Also she doesn't like being shut inside.

Would you be able to enclose part of your garden to make a catio? That way it should be possible to keep the neighbour's cat away from yours.

I'm gonna make her a better cat tree to make her feel safer and as a place to hide in.