Should I write off a love affair/friendship?

I have been involved with my friend/lover for 5 yrs. He has a vry demandng job tht requires him to wrk vry long hrs. In the past he seemed to be very supportive of me and my kids and vice versa. I have always made effrt to spprt his kids evnts and just be there when he needed anything. Lately, it seems that he is not as supprtve b/c of his work. He has not made any of my kids evnts and when I ask him for a favr he makes me feel like i am imposing. So as I became fed up I approched him. I simply stated if someone can be there 4 u in a relationshp, u should be able to offer the same in return and I also reminded him that I have always been there 4 him and his kids so I am not undrstandng the lack of supprt whn it comes down 2 me. He completly twistd my statemnt tellng me I am not friend b/c I keep count of everythng(not true) and I do thngs and bring it up and he will refrain frm askng for anythng else.