I would consider going to your parents, or other family, if that is a space that will be comfortable for you.
I had a breakdown in October 2017. I was off work for 6 months. I don't remember a lot about the early days but they were very similar to yours. I also was prescribed Sertraline. It may take a while to get the dosage right. Please keep seeing your GP regularly.
I would recommend setting up the simplest of routines and trying to stick to it. Try and get dressed every day and shower if you can bear it. Maybe a walk. Try and eat (I failed at this miserably but it's solid advice). Try and avoid mood altering substances.
Don't beat yourself up if you manage none of those things, just accept it and try again the next day. Be as kind to yourself as you would be to someone else.
Take the forms slowly. They can be done bit by bit. If you have a friend who's willing to help out, that's definitely something concrete they can help you do. Easier to dictate than write.
If you can access it, consider counselling. If you do be prepared for it to make you feel worse before you feel better. A good counsellor should not push you too hard too fast, but it will be a challenge. I considered it my 'work' at the time.
FWIW, and all experiences are different, I am now back at work full time. I have occasional hard days, but the good days are much more prevalent than the bad.
It may seem a long way off now, but you will come through this. This is a crisis point, but things will gradually improve. Don't be disheartened when really bad days strike, go through them, accept them and the next day will likely be better.
If all of that seems impossible and unrealistic right now, I get it, I'd just say keep it all in mind and when it feels doable do it, if it doesn't don't beat yourself up.
Just an internet stranger, but I really do wish you all the best. It's a horrible place to be and if someone had told me when I was mid-breakdown that I'd be where I am now I would have laughed at them. But I am, and you will be to. It will take time but that's ok.