Chronicles of blog visitors...

I'm a 22 years old but look way older than my age. Currently working and schooling too.
I have been in a relationship with a guy for 4 years, he was perfect and everything i ever wanted, but had a nasty temper.
It was the second year of our relationship he raised his hands on me.
We broke if off for a while, then came back together again after i forgave him.

He didn’t try it again until the next year. In all i have been hit more than 5 times by my boyfriend.
I have begged and pray for him to change, he promises and then falls back to his routine of getting angry easily over almost anything and using his fist to express his anger with him giving me the excuse that he grew up watching his dad hit his mum and that there’s no marriage which that doesn’t happen.
Now his proposing marriage, and i am at loss of what to do… I don't want to get married to a woman beater, but this is someone i love with all of my heart and have been with for 4years (my first relationship ever).
How do you stop loving someone who knows and accept all your faults? How and where do i start from? how do i function?
My friends advised me to be with him using the proverb; The devil you know is better than the angel you don't know.
Please what do i do, should i marry him all not?