I need help guys

My girlfriend just told me few months ago that she slept with a guy for money. This was the first week we started dating. Well we have a baby and live together but I checked our statements and this supposed guy she slept with send money at least 3 other times. So my head is racing to the point I think about it at least once a day. It sucks because I now just imagine this guy fucking my girlfriend every time. I don’t know what to do, I think it has messed with my head so much that I search on ph for videos of people and deception of what my girlfriend looks like to see proof, even though there’s nothing I’m going to find. I was doing great for years, but now i just pmo all the time and I can’t get over what happened. Her explanation was she didn’t have enough to pay for rent, and that the guy preyed on her for being in a vulnerable place. I love her and my baby with all my heart but it is just that I am unable to stop pmo, and the fact that she did what she did and with some guy who I never met but was around. And the fact she waited this long to tell me. I’m still with her and I don’t intend to leave her or cheat, or even end things. We have a great relationship since the first week. And I forgive her, but I need help to deal with my pmo, and moving past what happened. Much help from all you would be incredibly appreciated thank you

 

Thanks for your response

 

Thank you