Good. You are doing a good thing for yourself - stick with it.
I am currently in therapy. I just started and we have not touched much on this subject yet. She does know that it is an issue but we are focusing on my eating disorder first. Thanks
Masturbation is normal; what occurred between you and your sister is not normal. Now, it is important for you to get some help with this issue - it is having an influence on you all these years later. Generally, when people have been sexually abused during their childhood (particularly at age six or after) they do recall the mistreatment, though not in each and every instance. While what occurred with you and your sister is not within the bounds of normal, the salient issue now is what it means for you at this point. In one sense it is water over the dam, but in another sense the matter is very much alive for you - that is why you should seek therapy.