Sparkler1, it was so easy for me to ask the question "what is it you want from him or want him to do" but hard to answer it for myself. I'm not sure I ever did work out what I wanted. Or at least I did, but its not really practical - I want him to be the Dad I want and not the Dad I've got.
I wanted my father to make an effort, to try really hard, to ring me more than once a year, to sound pleased when he speaks to me, to be excited about my decision to adopt not send me a polite note 2 months after I told him, oh and so many other things.
I don't think my father has any conception of how his treatment of me made me feel, which I have to say sounds just like yours - that's why he thinks its all your problem/fault because he doesn't understand how good fathers behave, he doesn't understand the cause and effect of his behaviour on yours when you were really little more than a child.
But YOU understand it and the more you understand it the easier you will find it to deal with the situation. You need to understand that just because he treats you like you are unimportant, doesn't mean that you ARE unimportant. You are not going to a better or more valuable person if your father approves of you and gives you support. He on the other hand will be a MUCH better person if he gives you that support but you are both adults now and you can't make him into a different person at this stage of his life.
Learning to live with the fact that your father is a shit isn't fun and is like grieving for the father you should have had (or in my case did have), but it isn't any reflection on you. It's entirely about him and don't let your talk with him this evening persuade you otherwise.
Don't let him make you bitter, there are many people in your life I'm sure that care deeply for you and they are far more worthy of your time and emotional energy than he is, and they will repay that effort ten-fold. Take from him what you can/want to and make what you can of it but try not to waste too much energy on him and spend some more on others around you.
I hope with a good nights sleep you will feel better in the morning.