How to make him to understand my love?

Hi.. I fell in love with a guy about a year before and he is loving me for nearly 2 years. But i have not yet said to him that i love him. I see him everyday and he too sees me. He asked me "do you love me or not" only one time i.e. the day he proposed then he didnt ask me that question but he wished me on my birthday and gave gift. I think that he still loves me and now how i should let him know that i too love him? I wanna make him know that he's my love, he's my life.. How to do this??