How can I thank my guy friend?

Last night I got really drunk with some friends at a party and we videotaped it. I was throwing up all over the place. My guy friend picked me up and carried me to his home and put in his bed with a garabe can next to me. He stayed with me for a few hours until I went to sleep. I took off my clothes and I was just in my Victoria's Secret leopard print bra and thong. He went into his sister's room and got me one of her shirts and shorts and put them on me. He put an ice pak on my head to help get rid of my headache. This moring I asked him why he helped me since he was about to get laid with some other girl and he said that he wanted to make sure that I was safe. How can i thank him for being so sweet and helping me? We are both 19.