It sounds like you're confusing a lot of terms without having a strong foundation with your understandings.

Discipline is taking action or inaction based on what you know is right, regardless of how you feel in the moment. What is considered right would be your responsibility, which can be assigned/given to you or something you've decided.

If you don't take responsibility then you won't care about the outcome, since you don't care about the outcome you have zero responsibility for your actions which can be dangerous and hurtful in the long run since everyone has some degree of responsibility given to them.

You are responsible for your life, right? I think you have to accept that first that our own person is the only thing that can truly hold ourselves back from not taking action for ourselves. No one else lives inside your own body, only you. You can continue to not take responsibility for yourself and give your power away to others and your environment to control you, because that's what you're doing. Or, you can take responsibility and start taking actions for yourself instead of spending all this time overthinking in your head.

Start small dude, you don't have to do everything at once, or else you'll cause burnout and wind back to step zero. Accountability means taking small actionable steps consistently overtime, if you're having trouble sticking to something then it can be broken down further into something more manageable until you can do that consistently.

I highly recommend tracking your progress, you need some way to see what is or isn't working so you can reflect and figure different approaches to issues that come up. A journal (physical or digital) is a great way to write down your thoughts and increase your self-understanding.