Every time I think of my dad, I want to cry?

I am very sorry for your loss, I really am. Honestly, I feel that your emotional stress is coming from the fact that you haven't expressed your grief yet. You just have to give yourself one moment where you CAN cry it all out, and there's definitely nothing wrong with that. I may be completely wrong in saying this, but if the only reason you can't talk about him is because you're scared of the tears, you should find someone to talk to. Whether it be a friend or a relative. Sometimes I'm the type of person who doesn't want to share with someone close, just because I'm embarassed of saying everything to that person. In that case I talk to my friend's friend, who I haven't even met before, but who keeps in touch through the computer and phone. If that's the case, and you feel better venting to someone who you don't even know just because you feel less judged that way, talk to someone who's more distant from you -- you can even talk to me if that makes it easier for you. But I feel like the best way to get rid of the problem is to just give yourself a moment to let it all out. And always know, whether you're atheist or not, that your father would be proud to know that he meant so much in your life, and that him passing away from cancer only helped him get rid of the pains he would've suffered through if he were here today. I'm sorry if this answer is pointless to you, but I hope to get across that there's always someone who won't judge you from your tears, and you need to know that :)