Sweet but not attractive?

Im talking to this guy that Ive known a little less than a year and hes so super sweet to me. At first i didnt know he liked me because he really hadn't made it too obvious, plus I had my eye on someone else who I ended up with for 3 months. During those 3 months the other guy told me how he felt and said hed felt it for a couple months and that he just had to tell me but I told him I was happy with who I was with. After The guy i was with left, me and the one who liked me for a while started talking again and a mutual friend said that he talks about me all the time and i think thats so sweet. But hes not too attractive. Looks arnt everything to me but if you arnt even slightly good looking its hard for me to be with you. But im having mixed thought over this because he is an amazing guy (my teacher even tried getting me to go out with him!?) But im not physically attracted to him. What do I do?