Well, since we are sharing, here goes...
My ex and i were together for 9 years. Everything was great, so i thought. New kid, new house and a good job. I had worked late evenings our entire relationship. Spent every weekend with her and her family as much as i didnt really want to.
Eventually i got a strange feeling that things were not great. Long story short, i found out she had been cheating for 9 months. I took the blame that she gave me for not being home for her at night and we "worked through it" i took a job and commute i hated to be home at night. One year later i find out she had never stopped seeing the other guy. Vacation time to sleep around so as not to show pay discrepencies.
In the end, it was not my problems, it was hers. Took a long time to figure that out. Not saying this is your case, but again a tale of female deciet. I do not know your situation, and it is none of my business, but sometimes things happen for a reason. Perhaps you both need this and you will be stronger for it. Do not give up. I know its not easy, and hindsight and all... but you will survive my friend.
Again, lean on us, we will hold you up! You are our BROTHER.