Confused and lost

I’m 30sh years old, never been married and i guess i will never be, been with serious relationships that lasted for 5- 8 years but always ended as a failure. Im now in a relationship, wer going 8 years at the moment but things just rotated unexpectedly. This guy im with is what i say the perfect man for me, i can say that he’s an angel and we get along very very well, he showered me with words that i was the girl he’s been waiting for all this years, we talk about getting married and having kids, future was set, we dont argue often we never had problems like that. He also showered me with money and affection, all the luxury i can get just to make me feel i am loved. Until recently things changed. He started saying things that hurts the hell out of me, words that gave emotional damage to me, like i can live my life without you, giving conditions like not checking his emails ( which i NEVER checked one time i opened his email accidentally because it was saved in the computer) he says i should have my own set of friends as well as him, you see i was to focus on him i can say that my world revolved around him because i was so deeply in love. I admit my own fault, i became a total bum, i didnt give time for my career and i know i am wrong about that, i was just too focus on him that i wanted to be with him everyday and take care of him. But i was never controlling nor been a headache to him. In fact all i did was make him special everyday of his life so he wont feel alone or empty. I know that i should help him build our future together that’s why im studying again to set my career straight. Im doing this for myself im trying to think that way but back of my mind im doing it for us. We talked about his conditions and i accepted it, but the thing is he said that our relationship all depends on me now. That he can let go of me without any problem on his side because he is so ready to leave me, but he tells me that he still loves me and has never changed. When we talk its always been the same, its like there was never an issue. I confided on my friends and family they all said he might be cheating on you he must’ve found someone else he likes. I dont really know anymore what to do, its like i dont know him anymore, he told me that there was no assurance or security about our relationship for a future i felt like he can just give up and not fight for the relationship if things gone bad. I am so confused and a total wrecked, i dont know if i can live my life with someone whom ill be the only one carrying the burden to make the relationship work, how do i deal or how will i know that he really is cheating? that he found someone he thinks that is better than me? god knows how i love him more than my own life, i dont know anymore if he does still love me the same as before. Help me what i should think and do.