> Can you apply for a STEM extension now?

Unfortunately, I can not. I spoke with our international student advisor and it appears that I cannot get STEM extension. I need to be in post-OPT phase to get a STEM extension which I forfeited when I joined the PhD program. I can only get another post-completion OPT after I complete the PhD program.

I can get a pre-completion OPT, but as I quoted in another comment that is a limited option.

As each day passes by I am trying to digest the reality that I have to complete the PhD program. I am trying, but TBH I don't know how much I can force myself to do it. I am scared of my future, and I can't find a way out of this mess :'(