I-140 Help Needed and adjustment of status

[Hristo Enev]

I file I-140 week before my H2B visa expire , I did not FILE I-485 adjustment of status at this time . USCIS sait shows that my documents has been received , I got and job opportunite and they are willing to file for another H2B for me but today after conversation with their lawyer Im confused and scarred . She said that not filling I-485 with I-140 left me without status and I need to leave the country immediately ?
ANY HELP PLEASE ? Em I without any status and was not filling I-485 was mistake ? Whats my options now ? Can I file I-485 with backdate or Im illegal here ?