Steve,
I know exactly how you feel. You see, my mother did exactly the same thing to me when I was about to graduate from college. I was offered a good job that I really wanted and that was something of a long shot for me to get. Her response to the offer caused me to devalue it and ultimately reject it. I have regretted the decision ever since, and I have spent most of my adult life under-employed and risk-averse.
As I grew into adulthood, that job offer became just one illustration of an increasingly undeniable fact: My mother didn't want me to be happy. She didn't want me to achieve my goals. She didn't want me to connect with other people and develop a successful life independent of her.
Why? Who knows? And really, who cares? Once I genuinely accepted my mother's deficiencies--appalling though they were--I gradually came to realize that it's not up to me to explain them. I will never know the "why" of what she did to me. The important thing, for me, was to see things as they were (and are), to really understand that she does not create my experience, to listen to voices besides hers.
I am your age (43). My job offer happened over 20 years ago. Leaving a few years for graduate school, I imagine yours happened at least 15 years ago. Isn't it time to stop beating ourselves over the head with one missed opportunity and go forward? There's still a lot of time left, and while neither of us is going to be a wunderkind at our age, that's no reason to devote our lives to bitterness.
As you know, my mother died in 2006. While I miss her, I also feel an undeniable freedom, a lightness of spirit that I have not felt in many years. I don't have to worry about what to tell her, or what her reaction will be, ever again. I did my best to help her, but now I must show the same level of energy and concern in helping myself.
That doubt you feel is the internalized voice of your father. It may sound and feel like your own thought, but it isn't. And "realizing" that he's "worthless" as a father is only a small, small part of what you need to do. The harder task is to make your peace with the parts of him that you carry around in your own character. If your journey is anything like mine, you will be confused, angry, and hurt. It will take years. There will be moments when you aren't at all sure where the line is between hating yourself and hating the father-in-you. And the hardest part of all will be extending honest compassion and love to yourself--both the adult you are and the child you were--because only by doing that can you silence the incessant drumbeat of not-worthy-not-worthy-not-worthy that accompanies everything you do.
But I believe it is possible. I believe there's an "other side" to how you feel, and that you can get there. You can reclaim the person you are. You can listen to the voices that believed, and believe, in you, instead of those that don't.
You ask how anyone can be so evil. Steve, people are a great deal more evil than your father, or my mother. I refuse to give my mother any more power by demonizing her. She did what she did, and I have to clean up the mess. But so does everybody. Personally, I count myself very fortunate because I am not subject to the same forces. I can break free. I can see, and act on what I see.
And so can you. If you are depressed, you need to get treatment. Personally, I think this journey is impossible without a therapist, but of course that's an individual decision. But please know that you are not alone, and that we are all pulling for you.
best,
daylily
