What do you think of me running away and starting again somewhere else?
Why would you want to run away?
I need to get away from this situation, my girlfriend and I always argue about the same things
The desire to run away and start a new life might be appealing, but it is probably best to deal with the issue head on. It seems your relationship isn't working out and it is probably best to end it, which would probably help both you and your girlfriend.
How about we get married?
You should think carefully about getting married when you are also thinking it is time for you to end things. You need to do what makes you happy in the long run.