Woot, in the final analysis, you have to answer for your own actions, nothing that anyone else does is a reflection on you, you can't control their actions. So if you will regret not trying to rebuild the relationship then go for it. Take the precautions you need to that will protect your heart as much as you can, go to counseling, but if you can honestly say that you can truly go forward, building a better relationship than you had in the past and not drag up the past, beating her or yourself up over shit that's dead and gone, then do it. If you will spend the rest of your life regretting not trying, then do it.
If you're going to beat her up (and when I say that, I mean emotionally) and not be able to let go of the hurt and the actions you've both done, separately and apart, then just let the idea go with a clear conscience.
In the end, the only real question you have to answer is: Will you spend the rest of your life regretting not having tried?
It's hard to forgive hurt but the old line about "It's better to have loved and lost ..." still holds true. It's better to love with an honest heart than never have given that heart the chance to love.