I don't know what to do, I've lost everyone, HELP ME:'(?

At the weekend I had my ex boyfriend(Im not going to use his real name, so I'll call him Josh) and my best friend( same, not using her name so I'll call her Mary) stay at my house. So Josh and Mary* were staying at my house. I was going out with somone. Mary* fell asleep before me and Josh* did, but we just stayed up talking and **** about his new girlfriend and stuff like that. The next day Mary told people I had told her me and Josh had done stuff the night before, when she was asleep. She told people I had had seex with him and other sexual things. She told Josh* I had told her this stuff had happened. I NEVER said that though, because nothing happened. MY boyfriend rang me up saying Josh was upset and sitting in a road wanting to die, because everyone thought it had happened and they told his new girlfriend. Then he told me he never wants to speak to me again and he never wants to even see me again, and we're over. Now my bestfriend, my ex(josh*) or my ex who I just broke up with, don't like me. They have turned loads of people against me as well, for apparently Lying about doing things. I don't know what to do! No one believe me I never said we done anything! What should I do?:'(