I was in the same situation not so long ago. People are saying that being attractive (physically) shouldn't matter, but it does IMO. Yeah, you can get girls without being some super mega-stud, but if you are worried about your appearance going to the gym a couple times a week and getting a nice haircut and well-fitting clothes can make a world of difference in how people see you and
how you see yourself. THAT is the only reason that you should change- to improve your own self-confidence which is KEY to getting the ladies interested. Plus, it gives you something to talk about with that cute little cardio bunny in the short-shorts running on the treadmill.