My boyfriend has cheated on me more than 3 times with the same lady. I love him so much that its hurts me knowing that he still exist.

What is your question?

You should dump him as he obviously doesn't respect you or care about you. You say you love him but it's clear that he doesn't love you.

The question is should I leav him?. my heart is saying no but my my mind is ready to let go,we've been together for 3 years,m afraid to start a new r/ship

You're afraid to start a new relationship... so you'd rather be with this bum who cheats on you?

The thing is can you live with never knowing if this other woman is still in his life but he is learning better to hide her? Can you live with staying in a relationship where you know he had a thing with this women but now he may be settling for what he may see as second best?
Do yourself a favor and get out of this. If its not this woman who knows what women he might get with in the future. If he loves you and is giving you 100% of what he should in a relationship you would not be sitting at your computer asking US IF you should leave.

M scared what if the next person does the same thing?

You can't live on "what if"... you already know this guy is cheating so you want to put up with it just in case the next guy might also? Doesn't really make sense to me.

Ohk I leave him but I am going to mis him n I know he will back and apologz,how do I take it frm here now?

We all miss people that were in our lives at one point or another, but life is picking yourself up and loving yourself enough to not allow people to walk all over your emotions. We all have es that we had a hard time getting over.

Thank very much I can see the light now

Dump him and keep him dumped and stay out of all relationship until you have your confidence and dignity, and self respect back. You can have a lot of good clean fun without worrying about somebody screwing with your head, and heart.