All the things that make you sad about what your dad will miss - your high school years, seeing you get married, etc. are the same things that probably made him the saddest to know he'd miss them also. I guarantee he will always be with you. You'll have that extra protection. There is nothing worse than knowing you won't see your children grow up. To be there for them. Your mom is going through her own emotions and worried about you and your sister. There is likely an organization through the hospital that helps kids your age who have lost a parent. There you would have people who have gone through what you are going through. To say it will get better is not helpful at this point. You are doing all the right things. you are reaching out for help and verbalizing how you feel. That is a huge first step. There is a lot that you didn't understand at the time. The disease does not bring out what is truly the person at the time. Talk to your dad's family. Have them tell you stories about him when he was young, when he was a new father, how he and your mom met. Talk through a photo album. Then keep a journal so you can share with your kids some day the kind of guy your dad was. As they talk through memories with you, you're likely to remember more. My prayers are with you. You will always find an understanding friend on this site. Be strong, but know it is ok to cry whenever you need to.