What should I do about my girlfriend?

My girlfriend and I have been dating for a year now but since school ended we have been struggling. I bought her a phone to text me with because hers broke. It seems like she doesn't want to be bothered with me, but INSISTS that we get married(probably because I have a bright future) today we were hanging out and she barely said anything, she wouldn't kiss me, and later on she said she needed some 'alone time' what is happening? :/