Stop going to your father's house if there is anything laced with fentanyl in the house. You can be exposed to it easily.

Your inability to see your cat is (if I recall) a boundary your mother put in place because of behavior you were exhibiting while you were still living with her. I'm sorry your cat is so sick, but you not being able to see the cat is a consequence of choices you made.

I hope you get into a treatment center or a sober living soon.