this pain becomes unbearable

I was in a relationship with this man for 8 years. I loved him a lot. He is married and had his kid. When I got to know that he was about to have kid, I broke down since we had talked about having kids and maybe get married some day, if not get married atleast have kids. This seemed like the end of my dreams.
I was in lot of pain for months, I even told him that we should end it as going forward, he would be busy in his life and wont be able to give me much time, earlier also, he hardly used to give me time. But, he kept on saying that things havent changed and we could still be together. He wants to do the best for his kids, but our relationship can still be the same. I know him well, so I knew that going forward he would only get more involved at his home and wont give me any time. And I find it very hard to imagine how can I ever be ok with the fact that he had a child with someone else and he lives with them. I cried for months and decided to finally end it. I told him and we fought after they were born, we both said some very harsh things. I thought he also doesnt want to talk to me anymore, so I stopped communication with him.
But after few days, he contacted me. I couldnt stop thinking about him all the while, and couldnt control myself to talk to him. Finally, we started chatting once in a while. It was over a month since I had met him last, when I proposed to meet him because I miss him. I just couldnt get over him, knowing that there is only pain left for me in the relationship. I cant even talk to him about his kid, I become too emotional and cant bear to talk about it, it just breaks my heart even thinking about the situation. He doesnt seem to have any time for me, he is so busy in his life that even though he says he misses me, he seems happy. I dont even have the courage to talk to him about his current life at home. He very well knows about my emotional state. I had started feeling little normal when I wasnt talking to him much.
Again talking to him brings back the reality. When we made a plan to meet, he just seems so busy with things that it seems very difficult when we can finally meet. I miss him, want to see him. But, I know that the other things in his life will make it tougher for me. How long can I pretend that his family doenst exist, although they do. I dont know how to cope with so much pain, talking to him after so many days brought back the painful memories and I just couldnt control my tears after that.
I just feel that I wont be able to bear so much pain if I talk to him frequently. He says we will not talk about his kid. But I know that I wont be able to forget all that.
What do I do? I cant bear the pain. I feel sad talking to him because that brings back the painful truth. I feel sad when I dont as I miss him even then. WHen I talk to him, I control myself to not think about meeting him but finally I only ask him for it. When we are not able to meet, I realize that since he has other things in his life, he doesnt even give any priority to meet me. I dont feel at peace with either situation, what do I do?