I am sure it is all in the process to feel those feelings and to work through them with H in a nonjudgemental way. You need answers and after everything you definitely deserve them.
I understand the feeling of wondering having H there and wondering why he couldn't do that sooner. I am sure after as long as he had been gone, it is weird to incorporate him especially because he is being at home even more than he used to. All change and growing and growing hurts. So you will have times where you feel down, but make sure if H asks don't just say you are ok. If you don't feel like talking, let him know you are upset, but you don't feel like talking about it right then. Maybe that will give him the opportunity to reassure you and show some love.
Have a good week and I will be thinking of you and your family as your dad starts his treatments.
Me29 S3 H left 4/1/09 I file 8/2/10 Divorce final 5/17/11 1st http://www.tinyurl.com/25lhu52 2nd http://www.tinyurl.com/2c35ueg 3rd http://www.tinyurl.com/322yk89