I feel confused about healing from my Grandmother's death, how should I handle this?

First, my sincere condolences. Personal loss takes time to mourn, and every individual has his/her own timetable. If your father is as you describe, then it is best for you to resolve NOT to allow him to further manipulate you. You are an adult, and if you have a special project in mind, it will help enormously if you implement it. You might suggest to him to seek counseling for his issues, because you are not able to give him what he needs. This is not abandoning him; it is giving you a chance to heal and grow, and him an opportunity to face and try to fix his own problems. Good luck!