At the risk of sounding harsh, grow up.
How did your school ruin your grades? They didn’t do the exams for you, they didn’t even mark them. You had to revise for them, put in the time, energy and effort. COVID is not a valid excuse. Your amazing resit grades proved that was the case as well.
You could’ve applied to other courses through clearing, if medicine wasn’t possible. You could’ve waited again, reapplied for uni and/or medicine. Believe it or not there is not major harm in waiting or going to uni older than 18/19.
What course did you end up getting into? Why did you even pick it in the first place if you either a) didn’t want to do it or b) thought there was a chance you might end up doing it. Also, what is it you don’t like about it? The teaching, the modules, something else?
If you are doing something like biomedical sciences etc that can be converted or used to enter medicine after, it’s not all doom and gloom. But you’ve also said you don’t want to reapply for medicine, so simply you need to ask yourself - what do you want to do? What do you want to study? Where? Why?
If it was that bad, you could also have left if the uni didn’t let you change and for elsewhere. Wasting a year doing something you don’t want too, esp when so much money is being spent and everything that goes into it, you would been better off cutting your loss in the first term and then starting again the year later, as least then everything would feel more worth it.
Just because of all these perceived injustices and it being everyone else’s fault, you’ve stopped trying, putting in the work, time, energy and effort. It’s seems you’re have this poor frame of mind, with poor habits. That’s why YOU didn’t do the essays, YOU didn’t attend lectures, YOU don’t know the course material, YOU are unprepared.
All of that poor, negative attitude is what feeds into you not doing anything and ultimately likely to fail the first year (based on what you said). There is only one common theme in all of this.
Also, if you get poor grades in first year, other course and other uni are less likely to accept you because they’ll think you can’t handle to work or have the right attitude, and they might be onto something
If you don’t like it, leave and stop sulking. Grow up and behave like a mature person. Take some responsibility for yourself, your decisions, and your actions . There’s a lot in your power, but you’re choosing to do nothing good with em an that’s why you feel the way you do and are frustrated.