Withdrawing my resignation ?

If you really want to withdraw your resignation then talk to your boss and tell them that you would like to withdraw your resignation and see what they say. It may be possible to withdraw your resignation and it may not depending if they have already filled your position or if they don't want you to work there anymore.

If the company was trying to reduce staff in these pandemic times anyway, then they are unlikely to allow you to rescind your resignation.  I think you should take the other job, even if it's harder.  Change once in a while is good, it keeps you flexible.  And if the other company hired you, that's an indication that the position is not going to end, soon.

This is a question you should be asking your employer, not us. WE don't know what the situation is, or the job, or the problems you've had or not had--so what kind of advice are you actually looking for? CAN you withdraw it? You can try. SHOULD you withdraw it? Who knows. 

Discuss this with someone who actually CAN give you answers. 

Its totally up to your boss. But I would guess probably unless they hired and started training your replacement.

You ask your employer if you can withdraw the resignation.  Thy don't have to let you.

 I doubt you are such a valuable asset to the company that they'll do anything to keep you. You probably saved them the hassle of firing you. Actions carry consequences.

You can talk to your supervisor about it.

There is no requirement that they allow you to withdraw you resignation.