Freaking out for grad

So I'm currently on birth control and I've been switched about three times. Ever since I was on my last pack I've been bleeding and tmi but whenever I masturbate it bleeds a lot heavier and makes it last longer. Also I have grad in 3 days and I'm horrified I'll still be bleeding. I don't know what to do. (Plus I can't wear tampons and it's impossible to go to the bathroom in my dress)

It would be great if there was anyway to help slow down or stop the bleeding or some tips. Thanks!