Me and X were married for almost 10 years, dated 5. I left him 6 years ago, after a marriage full of resentment (me towards him). He didn't fulfill my emotional needs. I was so angry at him all the time because of it. When he tried to show me affection, etc. I pushed him away. Finally, I thought that being apart would be way better than being together and I left. Moved 250 miles away. I never thought he would file for D, nevertheless he did. D final since 2002. The first year he tried to get me to come back, but the anger overwhelmed me. I couldn't get past it. I hated him. After a while, I realized that alot of our problems was my insecurity issues and anger problems. After the first few years, I kept hinting that maybe we should try dating and see what happens. He always said sure, but we just never did. We have two children together and it was difficult to speak to him, because the children were always around and I didn't want to upset them any more then what they were. Finally, in March, we had a discussion about our relationship and he told me he still loved me.....and I told him I still loved him. He admitted to some of the problems in the marriage (this is the first he has done so). In May a job opportunity came up and I moved back to his area to be with my children and I asked again if there could ever be anything with us....he says, we should try to become friends (he doesn't trust me, I don't blame him for that....I had an affair right before I left).....and see if anything happens from there.....

I love him....I truly made the biggest mistake of my life by leaving. I don't know what to do. How can I show him that I am trustworthy and that I love him and desparately want him back?

By being the loving parent that your children need and showing him that you want his trust back at any means.
I am going through the same, well almost the same with my X. I cant be her friend after she ran off and jumped into bed with the first thing that came along. It hurts to love her but it hurts even more to hate her and resent what she did.

It will take a long time before I can truly be her friend and not be hateful and spiteful when she comes over to pick up the kids, such as my comment tongiht when she first came over, " How is cro-magnon man doing?" ( her boyfriend/ the guy she left me for looks like a cro-mag)

I had to explain to her that it hurt so much that she did what she did as soon as she did. We had only talked about the divorce and filed papers. She had sex with him 1 month to the day after she said that we need a seperation and she needs time.

Anyways back to you. Only time can heal what happened. You have to give him time to build his trust in you and be totally honest with him at all costs if you truly do still lvoe him. I suggest going to see a therapist. Not only will it help you talk to him but it will help you understand how he feels and how you feel.