how to end a relationship nicely ?

i have been in a relationship with a guy for three years now. we broke up a few months ago. and then started talking again.. he was absolutely distraught over this. he lost 20 lbs because he couldn't eat or sleep and cried everyday to me about how much he loves me, he would do anything for me.. said i can mold him into anything i want.. i guess i didnt realize he cared THIS much about me, so i thought to myself, i would regret it if i didnt give him another chance. we started talking again for about a month now, but i'm feeling that im not in love with him anymore. he completely depends on me emotionally because he comes from a very strict and judgmental family. also, our families come from two very different cultures and i really can't see this working in the future, without me making sacrifices. i'm still young (22) and he is a few years older. i don't know how to end it nicely, because i want to be his friend. i think he is a great guy but i just can't see a future with him. i feel like everytime he says i love you, i lie when i say it back. its easy for everyone to tell me to end it, but i can't bring myself to that point because i love him.. im just not IN LOVE with him. i dont want to hurt him. how can i do this nicely ??