Should i leave him or try to make things work?

heres the deal,ive been getting these feelings that my bf is cheating on me.im bipolar so i dont know if its really a gut feeling or if my mind is messing with me.ive asked him after 6 months of dating and living with him how he feels about me.he told me he didnt know.i wasnt looking for a love,just at least a 'im getting feelings for you' or 'i care about you'.fast forward a month and ive noticed our relationship is an 80-20.i do initiate all the moves in bed,and he never at least puts an arm around me for even 5 minutes while we are about to go to sleep.it also seems he tries to start fights.i tried talking to him about this and he got really snappy about it.i tried telling him i feel our relationship is fizzling out and he got snappy with that too.ive also got the feeling he keeps me around for money.i paid his whole rent this month.the relationship isnt all bad though.he kisses me every morning before he goes to work,he makes sure im fed,and there are moments like saying he would be worried if i didnt wear a life jacket in the kyak that shows he cares at least a little.but here lately ive been thinking of sleeping with another guy(since i only get to have once a week sometimes less) and almost went through with it.should i leave him if i try to tell him whats going on and he wont listen?