Whatever you're going through trust me it doesn't even come close to what your father have been through. You can never imagine that until you're in his shoes. He might have not given you the life you wanted but trust me he has done all his best. You'll never understand what fathers go through until you've lost them for good or you yourself become a father and see all the struggles for yourself. So stop trying to make it make sense and go ask him for forgiveness. And be genuine about it.