I can't cry. I let it out a bit more yesterday when talking to my sister about him but I feel guilty for not crying. I love him and he cared a lot about me. We were not quite as close in the last few years because I was ashamed of my thoughts (the stuff I post about here) and depressed so I distanced myself from everyone. That was a huge mistake. I wish we could have spent more time together. Fuck, FUCK. I feel empty and it's fucking bizarre to think that he's gone.
I'm so sorry for your loss. Guilt/regret is the worse feeling to let yourself get attached to and if you don't let go of it, it'll sink you. I lost someone I loved in November to suicide (so I feel it's similar to the suddenness), and I felt so guilty over it that it nearly drove me over the edge. Even now I still have random moments that cause me to break a little bit, but I think the best thing to do is to make sure you don't hold it in. Talk to someone about it, especially if you're feeling down/guilty/ashamed. Losing a parent is an unbelievable loss and one of the worst.
It's impossible to feel completely whole again, but after a while you'll adjust and things will be okay. Just think about what your dad would want and just keep going. Things will get better.