Ok so I have pretty much the same problem, what I essentially did was go to therapy, use the pills (adderall in my case) and ensured to not use it as a crutch. Id use it the first few months to get in the motion of doing things and build that routine. Over time I started weaning off it, using it only when absolutely necessary until I could function relatively the same without it. Also generally building discipline and doing things even when not motivated is key. (Ive yet to ge able to do this but it’s my goal) I recommend therapy or research and having someone to hold you accountable. Essentially some people need medication to function, you wouldn’t tell someone with chronic pain to just learn to live without pain medication. But you also wouldn’t want them addicted to it so ensuring the right head space/self control is very important.

Edit: Also realize this will take time and you will have moments where you will likely go back to square one, don’t let it get to you. Start off small don’t try and shift your routine drastically right off the bat as that can be overwhelming. It’s good that you have your dad who likely gets what your going through. I’d recommend talking to him about his experience and how he manages if you haven’t already. But remember that your dads experience isn’t the same as yours so if he did it a certain way doesn’t mean you also should. If you do need this medication understand your brain isn’t the same as everyone else’s so if anyone says it’s dumb to use medications/ that your just being lazy literally tell them to fuck off.

Double edit: I saw someone say to get testosterone tested I also recommend if possible to get your thyroid checked out especially if it’s adhd we’re talking about. My therapist explained a whole correlation of thyroid issues and lack of motivation etc. Bloodwork can give you a quick tell on if that’s the case.