Catching your Heartbroken - catching longterm bf with other girls nude photo

Me and my boyfriend have been together for a year and a half and are recently long distance. His emailed was automatically logged in on my computer and I scrolled through since Valentine's Day was coming up figured I'd get some ideas... I never do this I have you know. As I was looking I noticed a email he sent to himself back in June ( we would've been together 10 months then) I opened bed the email and there was a nude photo of a young women there. I don't know who she is and I know this was 8 months ago but I'm disturbed and heartbroken. Can anyone relate or give advice?