Mixed feelings all the time

Me and my boyfriend have been together for a year and 7 months now but it's been kinda rocky since day 1.

We argue a lot about little stupid stuff and we have broke up and got together plenty of times. But always get back together.

(Ig you can call it an on off relationship)

But he always expresses his deepest feelings for me. He talks about how he can't lose me and he needs me in his life. It's sweet but I always have mixed feelings.

Some days I love him but others (which is most of the time) I don't . I don't want to be with him sometimes but other times I do.

Idk how to just leave without breaking his hear.

How can I break up with him the best way?