Hey bud it sounds like you are going through a lot
But after you get tested given medication etc
Go buy a health cook book
Look at ingredients I.e different meat fish and veg etc
Then go home and try cooking it
Forget nuts and stuff might make u throw up try basic yummy foods
As for your eating habits try to ease of slowly so one week no take outs I.e subway
Then following week no cakes biscuits etc
And then once u start cutting these things out then you will enjoy the foods you bought and if you want a tip on Facebook and Instagram follow this guy called thebodycoach
Guy is excellent and just explains it in the most simplest way
I was same as you with different health problems but eventually it all helps
I got a long way to go myself but after couple of weeks taking control and cutting out a few things my levels have dropped
All the best to your health and seriously I think u will get better it's just when your diagnosed it's horrible and depressing
And plus I think with the bad eating and insulin shots resulted in your very lows in blood sugar
Good luck buddy
Xx