BJ i am so sorry that you had to go through all of this. I often hear people talk about how they think it was their fault or they deserved it but there is nothing anyone can possibly do to 'deserve' that. you were a victim whether you 'let it' happen or not and therefore it is NOT your fault. A lot of people i know talk about 'letting it' happen and i can honestly say that you are in no way to blame as people are scared or tired with it or just don't know what to do in these situations. it is in NO way 'letting it' happen and in no way does that mean it was your fault.
And as many people have said; it is a body's natural reaction (especially with children) so there is NO reason for that to make you feel guilty or sick. Often abusers get a 'kick' out of this reaction as it causes the victim more upset. you should never blame yourself for this.
And as for looking back and liking it; it is a memory, so you will remember your body reacting and your body may react at the thought of it, BUT that is completely normal. there is no way i would think of you as sick and i think nearly EVERY victim of abuse has thought like this so please do not be harsh on yourself.
sorry, i probably made no sense then.
take care (hugs)