You are definitely suffering from depression. Please get tot he doctor and get medication and therapy. It isn't fair to you or anyone else in your family. You have a family that needs you. Also remember, your father LIVES inside you. You know what he would say....YOU NEED TO DO IT! Remember, you want to make him proud. It is hard, but baby steps everyday!
You have to be strong You have 2 children and a wife to think about. I know how you feel because the same thing happened to me My only brother died at 36 my mother at 52 and my dad I am the only one left that took care of him I felt empty inside, when he died as i,am sure you do.Try to pick yourself up and to go on Each day will get easier God bless
You are depressed and you need to seek help for it. I too felt that way when my dad passed away 8 yrs ago. You need to learn to live for the moment. Example: for this moment in time, I am doing okay. You will have your good days and your bad days and these are things that you must do. I will tell you that as for you getting over losing your dad, everyday for the rest of your life it will always be on your mind. However, this being said, you need to get back into life now. So as bad and as hard as it is to do, it must be done, for the sake of your family.
You need to confide in your wife everything you are feeling. While I am not a doctor it seems to me you have only made a real attachment with your father and not with any other member of your family. I don't know if it is a trust issue or a fear of rejection. But you need to tell someone close to you what you are feeling.
Support groups are always a great tool, and many hospitals will provide you with this information when a patient dies, or upon request. Seeking the clergy if you are religous can also help. Even talking to your dad while you are alone can help if you have some unresolved issues.
You need to see your doctor and get some help. You seem to be suffering from depression. Taking something for a while will help relieve these symptoms. We never get over losing a parent, but the grief will lessen in time. Have you tried a grief support group? That is what they are there for. You do not have to do this alone. Surgery is never guaranteed, and a tumor must be delt with. I'm sorry for your loss. Please take care of yourself, as you know your Dad would want you to do.