Relationship with same .... uhh quite painfull?

i'm 18 and there is this person who i cant stop thinking about and he kinda knows i care for him and he thinks we are "friend" but not as much as i'd like he's got kinda of a social problem which is to say he's not intrested in getting close to any1 (myself included) and i'm not realy an expert in making friend either. i'm quite frustrated and i cant take it anymore and i cant let it go either. i love him but not ual i just want to with him as close friend