trust

My boyfriend and I have been together 6 months,and at the beginning it was great we had sex every day,he wanted to cuddle,and play fight all the time. I did somethings at the very beginning that be found out about and since then things are not the same. He tells me things are ok but I can fill a difference. He doesn't trust me with anything,like I lost 100 dollars n really have no clue to where I lost it at,and he thinks I did something else with it and says well im not speaking to you tell you come up with 100 dollars or you tell me the truth of where it went. I don't know what to do should I make something up that I did with it or what because I honestly didn't do anything with the money. Im so hurt he doesn't trust me like this