I filed my 2017 again in error. I do not have my 2018 W-2 as of yet. What can I do? Can i do it over again?

[DawnC0]

No, not if you have already transmitted your return.  You will need to wait until the IRS either accepts or rejects your return.  If rejected, you can go back in and file your 2018 taxes correctly.  If accepted, you will need to file an amendment, but that won't be available until after the IRS begins accepting returns (Jan 28th).  There is still plenty of time to get it straightened out, so just wait and see whether or not the IRS accepts or rejects your return at the end of the month and go from there.