How do I boost my self confidence?

I'm 30 years old and divorced and just had my girlfriend leave me because she said we didn't have enough in common. She said I was an island boy and she was a city girl. Maybe true but maybe she was just being nice. I feel reluctant to talk to girls because I'm afraid I have nothing to talk about and nothing in common with them. I like to surf, skateboard, swim, run, hike, workout. But not much of an intellect. Do I have low self esteem? Have I just not found the right girl? Do guys and girls have to have things in common to be in love? I thought guys were guys and girls were girls. They arent the same right? They are interested in differnt things right?