Mom thinks im on drugs?

Ok so recently ive been sort of depressed,social / girl issues DRAMA and family issues, and idk one of the times when my mom was yelling at me for really no reason she brought up my sleeping habits, and how it relates to drugs?? Well i got high 1 in my life dumb mistake but i doubt that changed me? She is accusing me of doing drugs at friends houses or after school wat so ever, she thinks im popping pills doing cocaine etc, is it cuz i love hanging out with my gangster friends or something? I mean they know im straight that i dont like drugs i like gaming, oh ya im a hard core gamer(play all night) my mom knows that i game but still acuses me?:0 wtf? How do i prove this? I was thinking a drug test or something idk