A 2018 1040X can only be mailed. The IRS is way backlogged with mailed returns. There are over a million 2019 tax returns that still have not been processed.
See this IRS newsroom release: https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue
Hopefully you mailed certified with return receipt or other tracking service as that is your only proof that the IRS even received it.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
