Gamma:
I keep going from no emotion at all to exploding with rage within minute intervals.
>>> IMO, "no emotion at all" is you holding it all in like holding a basket ball under water. Then "exploding with rage" is all those held in feelings bursting to the surface like an underwater basket ball might. It's just the pattern of stuffed down feelings that eventually have to burst forth.

My mom says I keep acting like some dumb, mindless zombie who doesn't ever show any emotion, but seriously I think I'm actually going to punch someone/thing because I'm so mad I feel like I'm going to scream. I have no clue why either.
>>> Your first task is to honestly and bravely examine exactly how you feel about certain things and who you are angry with. You need to identify the true and correct TARGET of your unhappiness and anger. I'd guess it's one or both of your parents.

Usually I'm the calmest person in the house and I usually never get this mad over anything. I have no clue how to deal with it peacefully and non destructively.
>>> IMO and experience, you need to first of all identify exactly who or what you are upset or angry with and why. Then you need to find a safe way to get it off your chest. You might need to write that person or thing a letter telling them EVERYTHING you feel and what you want done about the situation - it's a letter you may not send but just the writing of it will take a load off of you. You may have to figure out how to tell that person what you think and feel if it's safe to do it. You may have to follow another poster's recommendation to place that person in a (stuffed) chair and tell them all that you want to say, yell, scream, hit, beat, pound, etc. so you are expressing and venting your angry, frustrated energy towards the CORRECT TARGET (the person/thing you are angry with) and hopefully getting some relief from your held down feelings.
good luck,
jim