I really really really need help?

Hello, you can call me Ace. So, lately ive been depressed. Since its winterbreak most people are out with friends, but i sit at home doing nothing, I honestly hate life. Today I thought maybe I can feel better if I see friends. I brought my 40 dallors, and 2 pants I needed to return. To make a long story short, I lost about 60 or 70 dallors because I left my wallet somewhere inside the mall. I looked and couldnt find it. So i went home a cried, and cried. My step dad is very mean (just verbally) and loves to annoy me. Im with him everyday cause my mom works (and he is a teacher, so he gets winter break too) and Im soo stressed. Im pretty and love myself. My dad lives with his my mom (my grandma) and I love both of them to death and they are awesome. (no my dad isn a bum who still lives with mommy or anything) and so anyways... Ive started to cut myself, and it seems like the only thing in the world I can control. I havent told anyone, and if I do ill be in soo much trouble. Anyways when my mom got home from work I told her and now she is mad and keeps calling me miss forgetful. I went in the bathroom and cut myself and instintly cut myself. I dont know what to do anymore. Im not asking you guys to help me to stop cutting myself (cause i dont want to stop) all im asking is a way to cope and make myself less stressed and depressed, (that rymes :) ) and how to respond to my step dad when he purposly annoys me or makes me do EVERYTHING around the house. Also my step dad did this to my big brother too, and he starting becoming violent and went to jail, and got in soo many fights, and did drugs. Im never ever gonna smoke or do drugs because im a leader not a follower. My dad said he will pay me back the money I lost and he is always soo supportive to me. I only see him every other weekend and I just cant take it anymore. PS... dont worry I wont go and kill myself. Promise :)