Thanks everyone for your replies. I'm feeling pretty clear headed today which is quite unusual for me. I've decided that I'm not going to confess. I'm going to move on, concentrate on staying sober and get my life back on an even keel.
I'm really determined to leave the past behind and focus on the present. I don't know why but my gut feeling is telling me that confessing all is a really bad idea. The friends I've confided in have agreed with me. By telling them I feel like I've lifted a bit of a weight off my shoulders. I've also had some phone counselling with Relate and that was really helpful.
I feel like it would help to join one of the "class of..." threads on here. This is quite a lonely journey and I could do with all the support I can get.