SOMEONE PLEASE HELP ME WITH THIS!!! HOW CAN I HAVE MY BOY FRIEND FORGIVE ME!?

heirs the story...... when i was intoxacated i said stuff i shouldnt of about my bf to my cuzzin. about maybe hes cheating on me, nd stuff like that. and now he thinks im cheating on him and that i dont trust him but i do, i didnt mesn anything i was saying, and i tryd telling him this and he doesnt listin, he says that if i said it i mean it. which isnt true. we have bern together for 9 months this thursday. and im not cheating on him and never would. i love him to much!!!! how do i make him forgive me? and beleive me. i will take a lie deatectore test just to prove to him im telling the truth. but i dont think i can have anyway of takeing one. SO CAN SOMEONE PLEASE HELP ME WITH THIS SITUATION!!!