Hi! 😃
Please don't ever think you're a burden on others because of something that is out of your control. You're a human being first and foremost and not a human doing. Your father honestly sounds like a very toxic person and I would advise going no-contact or limit contact if possible because being in close contact with him does not sound like a healthy environment to be in. I'm so sorry you have to deal with such a person because I am sure it's very draining. It can also be very difficult and frustrating to deal with internalized ableism but it's something that can be helped.
Having a disability on its own can impact a person's confidence, and it's understandable why your father's statements would affect it, but you're ready to do things on your own and that's a great stepping stone! I hope that in the process, you meet some far less toxic and less judgemental people too. Your father may be related to you by blood, but please know that it has no bearing on the truthfulness of his words.
You kept going and stayed determined, which is great! You can cross that off a list of goals you have in mind, and you're already succeeding at what you want to do. I'm not sure if you've already tried this, but sometimes it can help if you write down statements you want to get out of your head on paper, and then destroy it (I know someone who found this helpful, they would burn the paper. I don't personally recommend using fire though!)
I honestly wish the best for you and hope things turn out in the best way possible and if you ever need someone to talk to, I'm here. Go kick some ass!!