Although you left P Company in February, sometimes some USCIS officers may not pay attendtion to it and thus, they may consider the date P Company revoked the H-1 petition as your last day of working for P Company. That is why I still suggest you to file I-485 and you may have a chance.
Of course, if the officer who handles your I-485 is serious, he/she may ask you to provide the last paycheck stub from P Company to prove the ending time of your employment in P Company.
Anyway, just file I-485 to see what happens.
Another choice is that you go to China to apply for H-1B visa. If the H-1B visa application is denied, you can apply for H-4 visa to come back.
After you return to US either with H-1B or H-4 visa, then you can file I-485 and your whole family also file I-485 together with you. I think this choice is better.
