My boyfriend cheated on me

We had only been together for around half a month, and on new years eve I had to spend it with family as my plans all went wrong. He had a small party at his house and he ‘did things’ with my so called best friend. He told me that he was really sorry and he was too drunk to remember, but I have recently been told by others that he wasnt as drunk as he claimed. I stayed with him, but it all got abit too much and I called it off. Over the time of us not being together he tried everything to get me back, this in a way showed me how much he did really care so we got back together. Our relationship now, is better than ever but it still bothers me. He always reasures me how much he loves me, and that it didnt mean anything and how it will never happen again. I do trust that he wont, but theres a small part of me that wonders. He says that he would never do it know because he loves me, and he didnt feel half as much for me then than he does now, I suppose in a way this shows that he wont because he loves me, but at the same time it makes me think, “so he didnt actually like me” I’m not sure what to do about this because I feel as if I love him too and I do not want to end it, but I can’t get it off my mind.

Any help would be much appreciated. Sorry for the really long story… x