What should I do if I shouldn't hurt him? I'm afraid...?

Hi! I'm Subzion & I'm 20. I'm doing part time job in a company for the past 9 months & it's a very big firm in Korea. The Managing Director, i.e the CEO's son is crazily in love with me. I haven't told him anything. He's 22 & the most handsome ever. He's rich & great hearten person. The whole city & myself have known him & his family for years that they are very good. He loves me like anything. I think he'll even die to prove his love. I'm very inspired & I like him too. But something is not allowing me to tell him 'yes'. I don't know what it is. I keep on hurting him by pushing him away & scolding him. Yet I look for every word he speak & every action he takes. Not even in movies a person could be this romantic. But despite the fact that he is the most eligible bachelor ever, my mind is not accepting to get into his arms. Why could this be? I know I love him. But I'm too scared if I'll be able to give back that much of love. He cares for me more than my mother does. So far, he's had only one girlfriend in his life & he broke up with her for she insulted me once. When I can realize his love this much, why can't I do something to make him happy? When he comes closer to me, my heart beat gets faster, I get some ticklish feelings in my stomach. Has this got anything to do with my stupid behavior. I want him to stay happy forever. For that I know I should agree to live with him forever. He already spoke about this to his parents and my sister and got their consent. I'm too worried about him for loving such a disgusting person like me. Please help. What should I do?