How can I control my bad temper?

And I've been through 4 phones in the last 6 months because of it. Everytime I get into an argument with my boyfriend and he pisses me off, I can't control myself and I throw my phone at the wall or floor breaking it. I try to stay calm but I cant. And today we got into an argument and since I dont have a cell phone I was on my house phone. He pissed me off and I threw my house phone on the wall breaking it. My dads gonna kill me. I'm normally the nicest and down to earth person you could meet, but ever since I been in love, my temper is crazy. How can I control throwing temper tantrums? They seem right at the time I'm doing it, but after I've cooled down I realize how dumb I was. HELP!!