Break uppppp

I think I wanna break up with my boyfriend. I don't know what to do. He's my absolute world and I love him to pieces I wouldn't be where I am now without him. He's my soul mate but I just feel like he's changed and anytime I tried to tell him he's changed he falls out with me and he won't change back. We have two holidays booked together with my and his family this year too so I have that to think about aswell. I just don't know what to do. Hello?????