Idk what to do anymore

So me and my girlfriend dated for about a year and a half before taking a break. The breakup lasted for probably 3 months, and we got back together. I asked her what she did during those 3 months because I just like to know what happened. Eventually I went through her old texts and found out she lied about everything she told me. Idk what to do. Should I forgive her? She lied to me while we are in a relationship, she said it was to protect me. But I asked what happened because I wanted to know, not because I wanted her to tell me what I wanted to hear. Help