Depending on where you live there may be a local sexual abuse advice service - I would suggest speaking with them - for advice about reporting or not, and for support in coming to terms with it. I think the risk might be why you want to report it now - if you want justice then I very much doubt that anything will be admitted or proven or taken forward now which may damage you even more, and if you want to be able to come to terms with it, then speaking to someone (e.g. a rape counsellor) might be more effective than reporting it now to the police.
Good luck