How can I get over Heath Ledger's death?

I didn't know him, but all the roles he chose to play were always amazing, and I felt like I knew him, especially after he ped. I'm a huge batman fanatic and when I see the movie I'm definitely going to cry, it's just so sad how he's alive in the movie, and buried in Australia in real life. I hate to think about it. Sometimes it makes me so angry to think that he died of something as preventable as a medicine OD. I know I didn't know him, but he definitely affected my life. How do I get over and stop being so sad over his death? and is this even normal?