so...I need advice

lately I've been really sad and anxious, I don't know why. I have these...urges, I guess you could say, to do bad things

just last night I had a mental breakdown in my brother's room bc he woke me up at 1:30 am when I have a huge test today

how do I cope? I know a few unhealthy ways, which suck since I've done them in the past, but I've never had a healthy way to cope​