I'm sorry you're unhappy with your Masters programme. Have you spoken to anyone at your university about this? One of your tutors or a member of university support services? Or even a fellow student such as a course or union rep?
If you really just hate the subject and the course then cutting your losses and walking away is certainly an option - but please don't think of it (or yourself) as a failure. Realising that something is not for you can be as valuable an experience as doing something that is, even if it doesn't feel like that at the time.
I started a PGCE when I finished my BA because I had no idea what else I wanted to do. Needless to say, I hated it and I dropped out of the course. So I've been there and I appreciate how hard that decision is - but it's a decision that got me out into the workplace and 11 years, one career, one marriage and a house purchase later, led me to taking an MA and PhD in order to pursue a career path that I actually want to do. So in hindsight I can see I did the right thing for me - and can take away what I learnt from that experience.
Your university can confirm whether you would be required to pay any further fees - other than tuition and accommodation though, I can't imagine there would be any further 'penalty' to pay for withdrawal from your course. The admin team of your department are probably the best people to contact to ask about that.
Before you do walk away though, I would urge you to talk to someone about how you feel. You don't really say why you've struggled with the modules but if you've been having a hard time with your mental health or life circumstances then you may qualify for an extension or re-sits on some modules, as well as an extension on any work still to submit. Given the impact of Covid-19 on the mental and physical well-being of students, many universities are being much more sympathetic to these requests than they would ordinarily (and, to be fair, my experience at Keele is they're usually pretty sympathetic anyway if you have a genuine reason for requesting).
Your university should also have support services in place - from academic support that might be able to help with proofreading, to additional meetings with tutors and academic/personal supervisors, and counselling and wellbeing support. If you're not getting offered any of this - or are unsure about what might be available and want someone to support you - talk to your student union rep and they should be able to help.
Take the decision that is right for you - there's no right or wrong here - but do talk it through with someone you trust from your university first. Hope that helps.
Amy