brother who always got what he wanted girls, cars from mom and dad etc, and me if it wasn't for my dad my mom would have aborted me when she found out she was pregnant. So imagine the love I got as a child
Firstly, I am sorry you find yourself here. We have all been through horrific experiences and know what you are feeling. This is survivable, although life changing - given your family of origin issues, this can be turned into a very positive event for you IF you allow it and take advantage of this gift - yes I said gift - that you have been given.
Secondly, the above quote from you moved me so very much. I believe this: Individual counseling is a MUST for you.
I went through several before I found the one that worked for me. He pulled his chair towards me, looked at me sincerely, and said, "How can I help you?" I said, "I am going to seem absolutely together. I am able to discuss each issue with clarity and insight, and I will seem ok. I am not ok. Don't let me bullshit you." And he didn't. He called me on everything, and we got through the immediate pain of infidelity and the loss of my husband and down into the shit of my dysfunctional family of origin and into the muck of childhood sexual abuse.
Your statement that you have kept in shape to stay attractive for her tells me one thing: Because of the insecurities you have about your mother not wanting you, your mom and dad always giving more to your brother, you have been playing this out in your marriage - doing the "pick me, pick me dance" - We, here at SI, pick you! We pick you to be a whole and self-loving man whose wife picks you, soberly, and only you, for the rest of your life. I believe that can happen!
Thirdly, If her story is correct - she drunkenly fell, he picked her up, she blacked out, woke up with an image of him on top - THAT IS RAPE. Why would she stuff it for 6 years - I stuffed my sexual assaults for 49 years! This is VERY common. It is also common to help or stay in contact with a sexual perpetrator who is family.
Perhaps there have been other infidelities and if that is so, she will need to come clean about that. The fact that you could suspect it, means there is much work to do.
My humble advice:
Put the "infidelity" on the back burner for the moment.
Take care of yourself with purpose: Eat well-whole grains, fish, chicken, nuts, fruits - no white flour, sugar or deep fried foods and limit dairy products, exercise, hydrate, ABSOLUTELY NO ALCOHOL, Go to your doctor and get temporary antidepressants and sleep aids, take vitamin B supplements, go get checked for STDs just to make sure you are ok and ease your mind.
Put physical intimacy on hold until YOU feel safe. If she loves you, she will wait. Don't do it to punish her, but to protect you.
Ask your wife to: stop drinking alcohol and go into counseling for herself - you can only ask - her mental and physical health is up to her.
No contact with brother from you or your wife at this point.
Blessings to you. Continue to post as you need. We are here for you. There are gifts waiting for you, if you choose to accept them.