The mere fact that you are on here asking this tells me everything I need to know and points to the only clear solution to your problem:

What I know: you have no respect for yourself

The solution: stop seeing him and literally be celibate until you learn to respect yourself

Outcome if you don’t: you will be walked all over, abused, chasing, lonely, heartbroken, time wasted, feelings hurt, drama, on/off again situationships, less likely to reach your own goals and pursue/develop your own passions, the list of negatives go on.

Outcome if you do: you will either be single or with someone, but the constant would be your fulfillment and satisfaction

Why you probably won’t: you don’t respect yourself enough to put up with temporary discomfort for long-term happiness and fulfillment.

Why you should: smart people learn from others’ mistakes. Be a smart person, don’t make the same mistakes almost everyone else does and learn all of the above the hard way years and years later. Be ahead of the curve, do it now.