Advice?

I've been with my boyfriend for about 9 months. We get along great but when we are upset things get bad. And for the first time it got physical. I know it's wrong and it's not ok and I won't make any excuses for it or him. We recently got engaged and bought a house together. In 9 months it's pretty fast but it felt so natural and so right. Now I'm lost and confused. Any advice?