I am just tired of relationship I am in

I am dating someone with whom I am in LDR. I love him a lot. When he is nice, he is really nice. But sometimes, I just feel like I want to give up on this. He thinks one of his friend is really pretty. He keeps on joking about sleeping with her. 99% of times he does this just to get a reaction out of me. But sometimes, I genuinely feel he really will just sleep with her if he gets a chance.

I just feel so disrespected and whenever I bring this topic out, he says I am just overreacting and I am insecure. Maybe I am insecure but he never makes me feel secure enough. I am just tired. I am done. I am not looking for any advice. Just want to pore my heart out. I am just so tired and I can't do this anymore.

I love him so much that idea of leaving him just breaks me. But being with him makes me question my self worth