I don't have a new job lined up. I just decided to quit... Because now I'm a full time university student for the next 3 years.

It's really lifted my mood. I've been coping with poor mental health for years. In 2020, I hit rock bottom and my doctor had to sign me off sick for a month. The time off sick made me realise how much work was a big factor in making me ill. It was a stressful low-paid job. Employee morale was low - even before the pandemic. When I handed in my notice, I immediately started to feel a heavily weight be lifted.
TL;DR - I quit my full time job to become a full time uni student. My mental health got better because of the change. :3