Let the day when your resignation officially starts be the day you learn how to separate you from being an EMT. Being a Paramedic is what I do, its not who I am. I genuinely enjoy my work for many reasons. But at the end of the day, its simply how I prefer to pay my bills, put food on my plate, and buy myself dumb **** from time to time. Its not my defining trait/feature/quality.
You have the right goals of being smart, educated, compassionate, and competent. Keep those, because we need that. But from my limited knowledge, you also overthink the hell out of this job and let it define you. Don't stop questioning yourself in a healthy manner. Learning from how you did (or didn't) do things is good and how you grow as a provider, but there is such a thing as too much of a good thing.
Your employer isn't helping. Its a lot of unnecessary stress as you've learned and I do think you're making the right call for yourself. But you also gotta learn how to get out of your own way or this won't be a sustainable career for you. Your last post is the prime example of why I say that.
Take some time away from the stress.
Focus on school while you make a new plan (not that you don't ever, but if you asked as many questions in class as you question yourself here, you'd be the smartest one in the room).
Get the hell out of your own way.
Start fresh and apply the things you've learned.
You'll do fine if you put the work in, but you can't be successful if you beat yourself. Thats all I got for ya.