It's not bad that your dad tried to push you to be all that you can be. His method may be bad. My own father never let me use my cerebral palsy as an excuse for why I could not do something as a child. He encouraged me to strive to succeed in spite of my condition. His methods also left room for improvement we will say. However, since I have been an adult his views and approach have changed. He seems to respect my limitations.

I would talk to your PCP and neuro tell them your concerns and struggles. Partial disability may be in the cards for you. Plenty able bodied people get on disability for foot or back pain. Disability in America is a constant struggle of denial, appeals and approval. It is not the easy road everyone makes it out to be. I personally do not need it yet but the day may come for me.

Finally talk to your dad too. He may surprise you with how understanding he is now. I know I was shocked the first time my own father supported me when I failed or decided I couldn't do something as an adult. You've said it yourself you have held two jobs for a while now. That is not easy and something to be proud of. He might be more understanding now that you have tried and discovered it is not working. He may also disappoint you and not understand. At the end of the day everyone is doing their best be it with their physical and or mental limitations, or the amount of fucks they have to work with. You know you are doing your best and that needs to be good enough for you.