my 13 year old son is going through the same issues... getting sexual thoughts & isnt able to control them he gets angry & very tensed... he looks frighten whenever those thoughts come on... he was an active kind & productive kid. These past few weeks his been walking under a dark cloud sad & very quiet. What scares me is that he does not talk at school and he is such a smart kid. we have tried talking to him & it works for a bit & then he falls back into that funk of anxiety...he got a MRI brain scan and we are waiting on the results.
some people with anxiety will feel guilty about things they did in there past. For example I thought I had HIV because I slept around before I finally met my fiancée. I thought I deserved to have HIV because I slept around before I met her and I felt guilty..... Crazy right??.... Anyways all boys develop differently, puberty is a weird transition for all boys, (and I'm assuming girls of course). Trust me most boys did something strange around the ages of 11-14. I certainly did and I know my friends also did. you need to forgive yourself for being a young curious boy going through a weird transition. You obviously didn't enjoy it, arent continuing acts like that, or some weirdo. You feel guilt, it's now time to forgive yourself and move on with life.