Ok ... mixed news to give you ... hopefully you waited for your original return to fully process before mailing in the amended return ... if you did ... amended returns usually take 4 months to process however the IRS did not process any amended returns for 3 months you can add that to the processing time as they play catch up ... and until the amended return has processed the stimulus will not be released.
If they do not release a stimulus based off the 2019 amended return then you can get the credit on the 2020 return you file next year.