Looking for advice! Please help?

My boyfriend and I have been together over 3 years now, I am an american woman, and he is from kosovo. Last week I found out through a friend that he has been dating another albanian woman for the past 6 months. I confronted him, and he denied everything, then the next day I talked to the woman on the phone. She informed me that they were planning on getting engaged and their parents have been arranging the marriage. The past week I have done everything to move on but it is very hard because i love him very much. After recieving conflicting texts from the "other" woman, I am more confused now than ever. I do not know if this was all a lie to make sure he is not in a realtionship with an american woman (his family is still very old fashioned) or if he really did cheat. I want to be able to follow my heart but i do not want to be a fool. Any advice will be appreciated. Thanks