That unexpected punch in the gut hurts every time.
I was told when one door closes another will open....I'm still waiting...

As a frog of little brain I'm not sure this will help.
First, decide if you really want to go back there to work. I know it's not a simple yes or no but try.

Second, if you haven't heard from your employer by next week call them. They will never remember to call you back.

Either present them with a plan for how you will correct the work or work habit that cause the problem now that you have been treated for your illness . . or

Ask if they will provide a positive evaluation of you work ethic over the # of years you have worked for them before becoming ill.

Be ready to provide examples either way and ready to seek other employment with a prepared resume before you call.

I had something similar happen to be when I first became ill. Unfortunately I lost my memory and could no longer perform the work I was hired to do. Now I have trouble with simple reading, writing and arithmetic let alone programming and data analysis. I have been placed disability as a result.

It is a rough situation to be in. Just convince yourself to be prepared, be the action part of the equation not the reactive part.

I hope things work out for you.