Filing taxes

So I was submitting my taxes and it kept saying my AGI for 2019 was wrong, I gave up on it after months but when the deadline started to approach I tried again and still nothing. I filed for an extension and it was approved and when that happened it wouldn’t let me try to fix my AGI anymore and still says it was approved. I haven’t gotten a update or any money back or even my stimulus checks and at this point I’m frustrated. Could someone please help me.