My fear/jealousy is driving my depersonalised partner away

My partner and I have been together for 4 years. We are in a long distance relationship and see each other every 6 weeks or so. He suffers from depersonalization disorder and is a very shy person. This is his first relationship. Due to his feelings of social awkwardness, most of his friends are online. He is not a very 'blokey' guy and finds that females make better friends for him.

In the early stages of our relationship, one of his online friends convinced him to break up with me because I was divorced. They had been friends for many years and she threatened to end the friendship if he didn't dump me. He depended heavily on her friendship and was scared to lose her as friends are so hard to make for him. He no longer talks to her since her manipulation and we repaired our relationship.

He also in the past (in the beginning of our relationship) used sex and live paid webcam sites, which he admitted to. He also contacted women on dating sites. He was a very lonely person with bad habits that had continued into our relationship, and he had real regret over this. He has since been faithful and loves me deeply.

The thing is, he still chats to women online, some he has known for years and now has started chatting to a new 'friend of an online friend' every few days. She is on his facebook and is very attractive and I'm just an average girl. He says there is nothing in it, and I do believe him, but I just wish I could stop feeling so jealous. I don't know why he needs to talk to these women but he insists that he needs a ‘female outlook’ on life.

I have tried many times to discuss this with him, but he gets very angry. He recently told me that he feels like he's not free to live his life as he's always worried that I'll get jealous. He said if he wants to stay out late he feels like he can't as I will get upset. I don't hound him if he goes out, but I admit I do worry.

I can't think what to do. He is a really nice guy and is very kind to me. We have recovered from his past mistakes and he is disgusted that he ever behaved that way. He is in the process of buying a home for us to move into together. But I am driving him away with my crazed jealousy. His remoteness just makes it harder. I try very hard to understand his distress and I always feel like I fail to do so.

Am I right to insist that he doesn't speak to women online? Is chatting harmless and am I just a selfish, jealous woman? Am I taking away a valuable outlet for him? I think he will leave me if I insist that he stops talking to girls online, but I am so miserable that I can't stop myself from forcing the issue.

Any advice would be so sincerely appreciated. Sorry for the long post. I feel much better just getting it off my chest.