Obssesive ex or cheating boyfriend?

I have been with my boyfriend for 2 years now. he is an OTR semi driver and is gone 6 days out of the week. we do not live together and once i had to go 5 months without seeing him. He doesnt have any social networking and neither do i due to the fact that i did cheat on him once in the past. He also tells me that he doesnt talk to other girls unless he has to. recently my brother found his facebok profile which he told me got hacked and he cant get rid of it. i snooped and i found comments he made on another girls photos calling her his "future wife" i snooped on her profile and i saw pictures of them together that i cant tell if they are recent or not and comments made by him or his facebook profile and that they are "engaged". I confronted him and he told me that it was his ex and that she was really obsessed with him and thats why they broke up. i contacted her but she did not respond. he told me he told her to leave us alone but she just laughed and is still on facebook. He wants me to believe him. but im not sure what to believe that she is an obsessive ex or that he is cheating on me. Please help me make sense of this.

The pictures on FB have dates on them, go back and look at the pictures & see if the dates are recent if they are, he's cheating. If they aren't. Then it's an old gf

I think you should trust your intuition. If it smells funny....it usually is. I myself am encountering same situation. It is sad when you realize someone is actually capable of saying and doing whatever to someone else....just so they can get ahead for themselves. Research it. Make a better effort to contact the girl without him knowing. Does he post his picture on Facebook or is he against the face recognition technology? That will be a sure sign that something funny may be play. Also does he take you out often in public places happily or irritated to some degree....pay attention to his actions and behaviors instead of his words at this point. The answers will come to light....it is just a matter of how long it takes to find truths.