Is he needy r using me?

Ok! I have been w/ my boyfriend for 4yrs and Im not happy anymore I havent been happy ever since nov 2010 wen I caught him sending pics of his ding dong 2 other girls which was the 3rd time he has done that since we have been 2gether. We have a 2 yr old together. He is needy like I stay broke cause of him. We stayed together for 4 months. He has another daughter a month and a half older than my child cause he broke up w/ me n 2008 had sex w/ his ex n got her preg. He never has money cause he stays n his own apt n pays child support 4 his oldest daughter. Im constantly takin him 2 wrk cuz out of the 4yrs he has bn thru 6 cars! They alwats quit on him cause he dnt take care of them im nt happy but I cnt let go cause he has nooo one 2 help him out. Im jus tired. If I break up w/ him he says im cheatin r ill never find n e one 2 help me like he did which he did help but jus nt enuff his mom says he has some growin up 2 do. I jus dont understand hw he never has money I stay on my own nw n im managing really well its jus money cuz I have 2 give him money cuz he is in need n gas is killin me he gave me $12 4rm his last check cuz he said he broke. Out of 4 yrs we have bn on 4 dates cuz he not the date type but damn we cn go every now n then im nt even sexually attracted 2 him but cnt leave cuz im 2 carin its more 2 it but 2 much 2 type...HELP!