I am hoping that you have a lawyer assisting you with your case. If you do, speak with your lawyer immediately; if you do not have a lawyer, consult with one as soon as possible. You may be eligible to 'port' your case to a new employer under very specific circumstances. I would urge you not to try to do this yourself. Good luck!
This answer is of a general nature and should not be relied upon as final, nor is it intended as legal advice. A consultation with an experienced attorney is always the best way to go.
Yes, assuming you have an EAD (or if you're in H1B status, you can file a change of employer petition, assuming you have recent paystubs at the time of filing). The priority date for EB3 is far off, but you should find a substantially comprable position (meaning the job duties are at least 50% the same), and should inform USCIS that you have ported your employment with an AC21 notice letter as soon as possible. This will preserve your GC sponsorship pursuant to AC21 regulations. Self-employment is also permissible to preserve your GC.