As this goes along, I don't think forgiviness is the hardest thing, you forgive, you want to stay together work things out rebuild repair or whatever you call it and so you do or try.
There is no lack of forgiviness (provided the CS really wants to stay in the relationship and wants to change) but when you look at them you see 2 faces almost 2 different people. The first one who you love, care for and want to be with and the second the one who didn't love you, didn't care, broke you in two with the brutal things they have done to you.
Besides lack of remorse or the infidelity not stopping or happening again, the inability to forget is what ultimately dooms an R.
I will touch her and then think is that where he touched her, is that how she sounded when she was with him, does she think about him when I touch her the same way he did?
The constant burden of seeing, remembering or imaging the details is what wears on you everyday to a point of breaking. They say time will make this better and while I hope for that and desire to stay in this relationship I wonder how long mentally and physically I will be able to hold out.