Epic post to Silly part II...
I had a complicated relationship with my dad too, with a lot of guilt involved. He was quite manipulative and good at laying the guilt trips on; I still don't know how much of that he did deliberately and how much was due to a lack of self-awareness. He was emotionally abusive (and occasionally physically violent) to my mother when they were married - they divorced when I was 11. He was a very selfish man. He relied a lot on me for emotional closeness and support. We were very close when I was a teen and into my early twenties, but I grew increasingly exasperated with his refusal to change. He was a depressive and heavy drinker/controlled alcoholic, and wouldn't make any positive changes, even when he was diagnosed with cirrhosis. He liked me to worry about him and nag him - it made him feel loved.
Around a decade ago, he was accused of something really terrible. Really really terrible. I still don't know whether it was true, and I will never know now, which I find very very very hard. It was a dreadful period, and I withdrew from him in a way that I hadn't before. He moved abroad and our relationship was strained until he died a couple of years ago. I slowly realised that although I still loved him, I didn't like the person I was starting to realise that he was. I didn't like the person who would lead the lifestyle he was living. We spoke regularly on the phone, which I really dreaded, because I felt the weight of his need for my love and support, and his need for me to care about him and worry about him and try to heal him. But I couldn't heal him Silly, any more than you can heal your dad. 
I felt guilty and angry and exasperated, and that manifested in my being sometimes quite cold and matter of fact about the fact that he was dying (whereas in my late teens/early twenties he used to regularly get drunk and bring up the subject of his death and how I 'musn't be upset' and I used to get very upset, and cry and ask him not to talk about it), which I think upset him. I didn't go and visit him in the 6 years he lived there, despite it being an 'idyllic' holiday location, because I just couldn't deal with it all.
He was dying slowly and unpleasantly of liver failure and had talked a lot about his death. He had a fall when drunk and was having odd symptoms in the days afterwards. I told him and told him to go to the fucking hospital. He didn't, and then collapsed, begged his gf not to call an ambulance but she did. I got a phonecall in the middle of the night from his hysterical gf (who he hadn't taught decent English to in the five yrs they'd been together because it suited him just fine that she couldn't hold a proper conversation with him) and doctors who wanted me to make the decision of whether to operate or not - he had a sub-dural haemorrhage, which is much more likely in heavy drinkers.
I almost decided to PM this to Silly instead, but then I thought 'well hereby hangs a cautionary tale for all of us as to where drinking leads us in the end' so I'm going to post it. Sorry for such an epic and depressing tale.
After much awful deliberation, I told them not to operate. I know what he wanted, and it wasn't that - he'd been very clear about it. The tale continues from there in exceedingly grim and sometime hilarious fashion (y'all know how dark my sense of humour is by now 
), but I won't bore you with that. The key thing is that he didn't die for another week, during which I should have gone over there. I didn't, for lots of reasons, and I was judged harshly for it, both by some family members, and by myself, deep down. My point Silly (ramblingly made as per usual) is that there has to be a line you draw between yourself and someone who has created the circumstances from which they want you to rescue them. Does that make sense? I couldn't rescue my dad from the person he'd chosen to be and the life he'd created for himself. And you can't either.
That doesn't mean I didn't care about him (for all of the huge fucked up mess of emotions I feel about him and what he did or didn't do), and I suspect you care about your father too, otherwise this wouldn't upset you so much. But stop feeling guilty, draw your lines and boundaries, and stick to them. His pain is not your responsibility, and you can't heal it.
Blimey. 
Sorry folks. I knew that'd be a bit of an outpouring, I do apologise.