Hang on in there. It does get easier. I promise.
Re the mental health: have you tried talking therapy? This really helped for me. Much more than any medication ever did.
Re the work situation: have you tried reducing your hours or working part time? I too also got diagnosed shortly after graduating from uni. I also quit work- for very similar reasons as you mentioned. I wanted to prioritise my health. I used to return from work exhausted. In hindsight I realise that I was very hasty in quitting work so fast. I found that my friends & family were busy at work & enjoying a life, whilst I stayed at home with not much productive time spent. This adversely affected my mental health. I am now in a new role where I work 3 days a week. It’s the best of both worlds.
Don’t be so quick to make a decision. Buy yourself some more time. Discuss the matter with your superiors at work & with your GP.
Best of luck