I m not able to decide....?

Hi, I got married 4 yrs back. Things were nvr like it wud have bn betwn a couple..he was alwys more involved in himself..reading..sleeping, watching TV..sitting on net..lot of other stuff wth which he was engaged...no phy relatn also..may be twice amonth...I was not happy all the while, I tried, i spoke to him many times about it..but he never cared...3 yr of our marriage, I think I didnt had any love for him..we lived like 2 ppl under same roof..I started makign frends..and fell for one guy...I stopped cing after 5 months..I felt I am doing something wrong to love someone else..Few days back, I got his pword somehow, I was checkin his mails and found tht he was deep in cyber S*X from past 4 yrs..thts the reason he alwys use to tell me at night tht he is tired n watch TV late nights..I m shattered..I dnt knw wat to do..I dnt love him anymre.