Amending one day after e-filing was not a good idea---that can just lead to confusion and delays. You should always wait until the original return has been fully processed and then amend if you need to. Slow down---wait until the original return has been fully processed. It can take weeks---or longer---before a mailed return shows up in the system, so not sure how you have determined that the amended return was lost.
If it has been at least a month, check here to see if the IRS has the amended return---and then do not expect quick results. It takes at least four months and often longer for the IRS to process an amended return.
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
If you e-filed the original tax return you should be able to e-file the amended return----but only if they really did not receive the mailed copy. If you have trouble e-filing, then it will have to be mailed. If you mail it, use a mailing service like certified mail so you will know it was received.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
