Unwelcome in my home

Context: I live in my parents home , where I grew up. My son whos one lives here too.I moved back in after the birth, rent prices are too dear for a college student. I have enough space such as my own sitting room and I do pay them €300 worth of rent a month.Ever since I moved in I have this unwelcoming feeling. A massive fight happened last year (2months after I moved back in). I went to live with my fiancé's sister for a few days but ultimately had to move back as I didn't want to become homeless with a 2 month old baby.I am never in their way since me and my child are gone from 7:30 till between 5&6:30 Monday to Friday and then my child is in bed by 7:30 and thats when I go up to my room because again I don't feel welcome.My mam does watch him sometimes and acts as though this means I owe her everything in the world. I do help around the house when I can at weekends because I am living here too. I buy the basic items such as milk,bread. Oil etc. and don't complain. I just feel family helping family is unconditional but whenever I receive help theres always something they want in return. They (mam + stepdad) act as though I should bow before them just because they are allowing me to live here.Recently, Our cat caught fleas so a big house clean was needed and the cat had to get the flea cream on. I clearly didnt want the cat inside as I know they can bite and i think they may have already bitten me. I didnt want my son being bit either. They kept letting her inside so I stated i do not want her in my sitting room at all. The next day I found her in there twice and now this morning as well after coughing up a hairball on the floor. Ive given out every time because it is disgusting having her in here and makes my skin crawl.I sent a text this morning because I was very annoyed because they kept doing it. And again I was met with 'this is my house I can do what I want 'and a sudden cancellation of plans to go out for lunch. I said nothing mean in those texts just expressed my concern of us getting bitten by fleas and how she isnt to be let in. My man said it wasnt her and that "i can try my luck saying it to my step dad' (my step dad gets mad quickly and shouts loudly) its like shes threatening me somehow.I am deeply unhappy here but I dont know what to do. I can't move out because I'm in college and who would rent share with a child. I just hate feeling unwelcome in a place I used to think was my home.Any advice on how I can improve relations with them or some how move out? via /r/Parenting https://ift.tt/2A75YXQ