How can i handle this heartbreaking issue?

My boyfriend and i have been together for quite some time now. his very good to me, and has taught me a lot in life. But at the same time i have weird feelings sometimes because his just too good to me. He has made me his first priority in his life and I thank him for that but i also tell him don't make me all there is you have to worry about life too!. Am i the same way? sure i have been at the point where he was the light of my day and the stars of the night but still get these weird feelings. When i talk to him memories come back and it makes me feel a whole lot better. but when im not talking to him its a different story. He forgave me for kissing my ex. being that where i come from thats nott normal at all and it would cause major problems but he understood and just warned me not to do it again or it would be over! On top of all this, he knows a family thats close to him. The men and women has 2 kids, boy and a girl. He was sent me pictures and there was the little girls picture. I may go to hell for this but She looks exactly like my boyfriend. I am soooooooooo scared, and i had confronted him he nearly had a heart attack for accusing him for fathering a married womens daughter. He thought i was insane and that id go to hell for that bc she was all this great and like a sister to him. He got very offended. I know people look alike, but i mean oh god i wish i could shw u pictures, the eyes, eyebrows, lips, neck aaaaahh..she is 4 and half yrs old and he had met the family 6 yrs ago. So we had our fight and i asked him to forgive me, he did, than tonight, he went over there as a guest, actually been to their house for a couple of days, they consider each other like family. So i asked to go on camera and bring the kids too. MY GODNESS did she look like him. She also looks like her uncle. but the way she was walking, smiling, her little tummy, her hands. and her brother looked very pale longer fingers, had totally different features. Just a bit a like. the boy looks like his father. and the girl just looks like my boyfriend. i said to him oh my god she looks soooooooo much like u in a joking way and he took it as a joke and said pleaseeeee don't start that again god forbidden. He is an educated man. So he has an answer to everything. Despise the fact that his sooooooooo good to me i hate to accuse him of it again. It literally made me puke when i saw them to up close. I think he maybe the father. And im asking god nd anyone here that reads this to forgive me if im over reacting but My instincts are killing me. His far from me so i cannot do a DNA or i would even though it ould had to be with out their knowledge, the only way i can do that is to get married and move there with him according to family and cultural and religious traditions. Any ideas or similar stories you have and how did you resolve this issue??????? I am In deep pain and thinking of it makes me wanna puke!!!!!! His a good person to be looked at this way but my gutttt is jumping out of proportion when i see them 2. please help!