Need help nobody understands me?

I need help to understand something me and my family had a fight today about why I am in a mood all the time and I have explained to my mom how I feel about her kids that are 9 and 13 years old I have been in there life for 6 years now and it seems like i haven't gotten anywhere I told there mom how I truly feel and she just wants me to be happy in these boys lives but I feel I am only here to do things with them other than that if I didn't they wouldn't want to be around me anymore there mom told me forcing it isn't gonna be acceptable I am not even trying to do that I am trying to be a brother and a family member to this kids and she even said over text that he will be my brother if I don't pressure him into it but now she is saying something different I have to ether be full in or I would have to move out cause I am being forced to have a bond and do things with them or else I am asked to move out and I can't seem to get my mom to understand what I am feeling and how I get her to understand I don't want a relationship with her or the kids anymore I feel used and there mom only wants me around to do things with them my mom will say thats not the case at all I am over thinking we had to move out the first time cause me and her relationship wasn't good and we couldn't do the fighting anymore so we ended up moving into our own house and I was totally fine what can I do from here ? make this better and make my mom see my side of things and not always be on her side?