Urgent advice needed about coming clean

I have been with my partner for over a year now but when we got together he made it clear he was very uncomfortable with my sexual history - he understood i had one but i think he prefered to think of me as just being his, im not sure. He has a somewhat more colourful sexual history than me which doesnt bother me in the slightest, as long as he's only being with me thats all i care about. When we came to have the TALK just to clear the air over what we had previously experienced, i worried about telling him the truth about mine because i thought he wouldnt be able to handle it and would decide he couldnt date me. now obviously i made the terrible decision to lie about it. To me it wasnt a malicious lie - i had a one off with a guy that i thought liked me a few months before we met and OBVIOUSLY i got that wrong because he didnt call and it ended up being more or less a one night stand. I knew my boyfriend wouldnt understand so i mellowed it out to portray it as being a relationship to make it sound better and also because i was embarrassed. I thought as long as he knew my number that would be fine. However we finally had a chat the other night about my boyfriends sexual history and how he is ashamed of it and now i wish i had told him the truth about mine because maybe he wouldve understood, except now ive spent a year lying about it and i dont know how to even begin to tell him the truth. He already suffers from trust issues and i know that he'll either completely understand why i lied or lose all trust in me completely. (he is very extreme). I absolutely love this guy and in a way i dont regret lying because weve shared so much wonderful time together that we not have if i had told him at the beginning. I know this may not seem like too big a problem to many people but this is something that i've been anxious about for so long and i just dont know whether its worth telling him at all or how to tell him if i do. Any advice would be appreciated.

Basically, you need to look at the fact that it's none of anyone's business what you did before you met and this applies to you and your BF. It's the easiest way to not go down the path of knowing what you did with who in the past. If your BF is ashamed of his past, then it's his issue to sort and if he has trust issues then, again, it's his issue to sort. You shouldn't have to change or do anything to fix his lack of trust, rather he needs to be mature about it and you need to realise that he's insecurity is something that you need to take on board if you need to be with him. He also needs to understand that even if you guys share your entire lives together, he will never own you. Sure, you can be committed to each other but it's love, trust and respect for each other which concretes everything together. It wouldn't matter what you told him about your past because his attitude and insecurity only clouds the issue and therefore it's always best to leave the past alone...it's for learning from, not for living in.