I Really Need Help!!

T
I am a man btw. My gf showed this to me and I loved how supportive the women were of one another so I made one to get the female perspective on details of my relationship. So to begin, I have been with my Gf since my freshman year of hs  (we are juniors now) and my love for her has only grown stronger by the day. I know she is the woman I want to grow old with. We've been unable to see eye to eye a lot lately and I'm worried. We've gotten into arguments in which we've both said things we didn't mean at all but the pain still lingers. No matter what I'm rockin for my lady but it hasn't been the same on her end. We've had very brief periods of time where she'd resort to other people (being males) instead of trying to work it out with me and it hurts. I want my princess to feel confident enough to be able to come to me and open her mind about anything. What can I do?