Cheating / forgiveness issue

Let's say you found out your partner cheated on you. You argue about it and you decide to stay to work it out. How long do you think it would take you to get over what they did and not constantly bring it up? A year, 2 years, 8 years.

The reason I'm asking is because during the course of my relationship with my wife she and I have both stepped out of the relationship. She feels that since hers happened before we got married that shouldn't hold as much weight as me who did it after we got married. What I did was some 8 years ago. Yes, we've been to numerous counselors to get past it and just when you think you've turned a corner I'll do something completely innocent that my wife sees as suspect. If I go to the store at night then that's suspicious. If I'm sitting and she can't see what I'm doing on my phone, that's suspect. If I get a text message, look at it, but don't tell her who it is then that's suspect for her. Again, 8 years ago and she's still treating this like I did it last year. WE recently started seeing a new counselor to work on a few things and during the course of our 1st session it was focused solely on my and my cheating. No, it was not an affair, just a one time hook up with a girl I met online. Again, can I stress 8 years ago. However, she too hasn't been 100% faithful. Yes, I was angry and forgave her and I/we moved on from that. I don't look at everything she does as suspect. Sometimes she'll get up and just leave the house without saying a word but that doesn't bother me. Let me grab my keys just to go get something out of my truck and she starts up with the 20 questions. Yes, we both were wrong but why is it fait for her to hold me to a higher standard than I held her? She cheated too but I'm the one still suffering, again, 8 years later.