My father died very suddenly about a year ago. It came as a total shock - one day he was just gone. I walked around in a daze for a few months, and I'll admit that it was nearly six months before I started to get back on my feet.
This was one of the toughest things that has ever happened to me, and it definitely changed me. So here's what has helped me to recover
I think that the biggest thing that helps is time - losing a parent is a profound experience, and not one that you can easily cope with. There is really no way to prepare for it. I still think about my father nearly every day, and it's hard to believe that he's gone. But, as time has gone on, I've definitely managed to put it into some sort of perspective. I can't say that it is a positive experience, but I've learned to value the time I do have. My father was twice my age, so maybe I've used up half my time. I had better make that time count.
Another thing that helps is taking a break. It's fine to take a little bit of time for yourself to get things together. It's interesting to see how people respond to the death of a family member - a lot of people try to fill the hole by throwing themselves into a frenzy of activities. Eventually, though, you have to face yourself and make peace if you want to recover.
Finding stability in your life is also important. When my father died, I was working on a startup. The startup was on its last legs, but his death completely threw things off balance for me. I felt like I was floating for a long time, and decided that I needed to add some stability to my life. Just too many things were uncertain at the time, and I couldn't deal with that. About six months ago, I decided to take a job with a more established startup. I feel like adding some stability to my life has definitely helped to put things back to normal. This was kind of the last thing on my mind for several years before that, but in this particular case, I think that it helped me to recover.
Finally, I think it's important to talk about it with people. I'm sure that you have friends who have lost parents - talk to them about the experience. If you have siblings, talk to them. You will find out that a lot of what's going through your head is stuff that everyone experiences. I wish that I had done more of this - I feel like I kind of shut down and didn't really want to talk about it for a while. If you need to (and maybe if you don't think you need do), seek out professional help. They are trained to help people who have been through this sort of experience.