Glad to see you've decided to join in the discussion, but sorry it's necessary for you to be here.
Abuse is still abuse no matter the age. No means no, regardless.
Everyone has their own story, and is healing in their own unique way. Professional help from someone trained in CSA is sometime necessary to make a lot of progress, but support empathy and understanding are always needed, and I hope you find them at MS.
Best wishes and good luck as you deal with the doubt and guilt on your journey of healing and recovery.
Never, never, never, never give up...Winston Churchill