Messed up and put myself as "can be claimed as dependent" for 2019. Sent an amended tax return, but no word yet. How will I get the stimulus check since I qualify?

Because of Covid-19 IRS is very short staffed and processing mailed in returns will be delayed.  

If your return is not processed for the stimulus payments, based on our understanding payments will be reconciled on the 2020 tax return, filed in the Spring of 2021.  If you qualify at that time for payment, you will get it included in that filing.

Please check this link for updates as they are available:  Covid-19 Updates