Friendship problems

So I have this group of really nice friends and they are probably my only friends ( there’s 5 of them ) but recently I just don’t feel like I belong with them anymore and I don’t know anyone else at the school that likes me cause I got bullied a lot in my first year of high school and there’s really stupid rumours about me that people still believe. I’m also an introvert so I never hang out with them on the weekend and they have started to get angry at me cause they think I’m trying not to be there friends and there are occasions where I will go hang out with them. My mum is really worried for me cause I’ve never had a good experience at school and thinks it would be best if I change schools but for some reason I think that would make things worse. I really don’t know what to do and it makes me so upset cause if I lose the bond I have with these girls there’s nothing for me except just sitting in the library by my self what do I do ?