My girlfriend cheated on me with my best friend. I found out this morning when my friend admitted to sleeping with her, and showed me the pictures he took of her naked. When I confronted my girlfriend she said its because "I'm terrible in bed". I was repeatedly sexually abused when I was 8 years old, and I find sex too hard deal with. The whole thing is too emotional for me, and she knows this. I love her so should I forgive her?