What's the meaning of his behaviour...???? Is he a real cheat..?

Well...My boyfriend told me that he want to stop our 3years relation and he want to be my best friend for rest of our life. We can't part because we are doing a business together. We had regular sexual relation and i agreed to stop this relation with much pain because he says his family will be against our relation as i am elder to him and a divorcee. I love him so much that i can't still spend one day without seeing him and every single moment i think about him. Now he asks me that he miss sex and he wanna do it with some other gals which make me feel really bad. Now he starts to flirt with my colleague infront of me and when i question this, he says we ended our relation so i don't have the right to question him.He used to abuse me daily and I feel like mad and can't go on like this. What will i do to get over from this depressed stage and wanna know his behaviour is normal ? I think he was using me past few years and now just rejected me like this..Please any good suggestions..???