I'm so sorry to hear about your loss, Dark Asylum.
I know you have already picked up on it, and it isn't much comfort, but it's true - your father would not want you to give up your sobriety because of this. Like hypochondriac says, whatever you do, please don't drink.
My cousin (who was also my foster sister) killed herself and I understand how difficult this must be for you. I used alcohol to numb the pain for a long time, and eventually I realised that it was completely futile. You have been sober for a long time and you should be proud of yourself.
Please go to your doctor and ask for some help. CBT is widely available and helped me endlessly in dealing with grief and other issues, such as self hatred.
Hugs x