My girlfriend doesn't like PDA at all. Anytime I try to hold her hand in public, she swats my hand away and says, "Don't." Yesterday, we were at the mall and I tried kissing her on the cheek and she told me to "stop embarrassing her." We're in college. It's not like I go overboard with PDA. The only thing she lets me do in public is walk close to her. I feel like I'm not good enough for her. What do I do?