I've already filed and received my tax return and accidentally signed up for the stimulus registration what do I do to fix this?

The IRS should reject your stimulus registration since you have already filed your tax returns.

For more information you can visit the following links for the most recent updates:

TurboTax Corona Virus Updates or IRS Corona Tax Relief.

I've just received an email saying my stimulus submission was accepted.

Excellent!  That good information to have.