I feel bad

I feel bad for what I am doing I told my ex to move on from me and that i will always love him but he has to move on and that he will understand why I'm letting him go later and his girl best friend told me he was a bit upset yesterday cuz of me but I have to let him go I'm not right for him I'm not good to be his gf but I feel bad cuz ik he's alr upset at me idk what to do anymore I know he really loves me and I love him but he's not the problem I am that's why I am letting him go I told him we can still be friends if that's what he wants or to not talk to each other I just feel guilty what should I do