I can relate to this. I just began seeking help after 15 years of holding it in. I used to feel like I didn't fit the "standard" or "mold" of sexual abuse because mine was child to child as well, but there IS no standard or mold. Don't ever try to 'unvalidate' what happened to you. If it happened in secret and you didn't want it, it was abuse, regardless of the age, sex, or relationship of the victim and abuser.

I've started going to psychotherapy about 6 weeks ago. I believe that therapy can be beneficial for everyone, even people who may have experienced trauma. So my advice is yes, I would recommend treatment at some point in your life, if you find yourself comfortable with opening up to it. I'm finding connections for the reasons I am the way I am, or why I feel certain ways about myself, and its helping me compartmentalize my life while unassociating my past sexual abuse from my present sexuality.

My therapist is taking the process slow and although its painful, it would be more painful to keep suppressing my sadness. I feel like my life is buffering, my sexuality is stunted, and life is weird, hopeless, and sad. The process is slow and both the happiness and sadness comes in waves. I guess my best advice is that life is short and although something truly horrific happened to you, that shouldn't stop you from treating yourself to living a life as happily as everyone deserves to. Just because someone else did something bad to you in your childhood doesn't mean they should be able to control your state of mind during your adulthood. Happiness is an inside job, but experts can help guide you there.

Good luck. It doesn't feel like it during present time, but in the future, it will get better. And then you'll look back, and maybe wish you could have believed it sooner :)