I can't imagine what it's like seeing your Dad like that Andrew. I'm sure that your Dad is your hero. I know mine is. It must be unbelievably difficult to see it happening. However, think how far he's come in the last few weeks? I'm sure day by day, week by week then month by month you'll see improvements. It's going to be a huge lifestyle change for you all but count yourself lucky that he's here. I'm sure with the medical attention and family support that he can make as full a recovery as his body will allow.
Best of luck on the long road ahead, just remember that there are a lot of people here to offer support. We might not understand what you're going through but we can sympathise.