I filed my 2019 fed return too early. The income is much higher than 2018. That will make me get much less from Trump's stimulant check. Anything I can do now?

[DoninGA]

No.  There is nothing you can do now, unless you amend the 2019 tax return with tax data which would lower your 2019 AGI.

See this IRS website for stimulus payment information - https://www.irs.gov/coronavirus/economic-impact-payment-information-center

[NCperson]

@hyperyan but there is hope! 

What is really occurring is that the rebates are an ESTIMATE  using 2019 (or 2018) as the basis of the estimate. 

when you file for 2020, you will use that income to determine your stimulus relate

if you are owed more, you'll get that rebate as part of the 2020 tax return*

if you received too much, you are not required by law to return it, 

parents that have children in 2020 will actually receive a $500 rebate next year even though the child wasn't living in either 2018 or 2019!