My employer had my SSN wrong on my W-2 for several years and I just found out. I filed my taxes successfully with my correct SSN. Which number will the IRS have for me now?

Your problems is with the Social Security Administration.

Find out if your wages have been properly credited to you for those years.

How did you manage to file all those years with a bad W-2 ?

The IRS has your correct Social Security number. You should make sure that your employer corrects your Social Security number promptly. And, as fanfare said, check your Social Security earnings record. You will probably have to get the Social Security Administration to correct it. See the following FAQs on the Social Security web site.

How can I get a Social Security Statement that shows a record of my earnings and an estimate of my future benefits?

How do I correct my earnings record?

I checked with the SSA and all my earnings are accurate and up to date. I honestly don’t know how I was able to do my taxes correctly with that error, other than I personally entered them using TurboTax. I manually entered each monetary amount and my correct ssn from my W-2 and it was successful. 
I also haven’t received my stimulus, so I’m guessing they’re  connected. I’m awaiting a corrected W2 but honestly it it sounds like a lot of corrections to do and I can’t wait that long for my benefits...

Go here:  https://www.irs.gov/coronavirus/economic-impact-payments

This FAQ site may also answer your questions.

https://www.irs.gov/coronavirus/economic-impact-payment-information-center