I am not sure why you signed contract before you even file your I-140, but I think you can find an excuse to tell your lawyer that you'd like to file I-1485 without their help.
File I-485 is not too complicated; many people did themselves and succeeded, because would do nothing except fill the forms, which you can do either. So just talk to your lawyer see if you can terminate your contract and if any penalty, how much.
File I-485 is not too complicated; many people did themselves and succeeded, because would do nothing except fill the forms, which you can do either. So just talk to your lawyer see if you can terminate your contract and if any penalty, how much.