When someone :(

i'm in love with some1 since 2008 and im sure that he loves me too ,, but suddenly he stopped calling me and i contacted him by email asking him why he never pick up the phone or call me back .. he sent me an email and i'll copy it ( I love u.. but.. I dont know if i want to be with you.) which made me really sad ,, cuz i felt like he used me .. i really love him to death .. and he knows that .. we have the same interests and the same likes which made me love him more and more.. i met him on the internet through a site after while he took my msn adress and start telling me about his life and stuff and the gal he loved after one year i was sure that he's the one after i knew that he really loves me but now everything changed... ??

why ppl do u think he sent me this email ? i feel like he may have some problems cuz i know him he have lots of problems but he dont tell me about them deeply? what i suppose to do ?? i really need some answers ?? if u were me ,what u'll do ??