Please stop using "ABC (company)"! It looks as if that's what you're actually going to write in the finished article. Ideally, make up (invent) a company name and use that. Failing that, put the words "name of company" in square brackets. This is what I mean:
1. After my firing at Popsicle Ltd, they fired ...
2. After my firing at [name of company], they fired ...
I find "After my firing" unnatural. Use either "After I was fired by [name of company], ..." or "After [name of company] fired me, ...".
Note where I have added commas.