I had to amend my tax return, i only needed to add 2 new w/2 forms. It’s already been three weeks passed, I have not heard from anything about my amended return. What do I do next?

Amended returns can only be printed, signed and mailed in....did you do that?   It can take upwards of 16 weeks for an amended return to complete processing....you should be able to check on it to be sure they received it after 3-5 weeks though.

https://www.irs.gov/filing/wheres-my-amended-return

I already printed, signed, and mailed my 1040x form and w/2 forms already to the building in Austin, TX. My letter got to the location 3 weeks ago, but I have not gotten any update yet, and I’m not sure what to do.

All you can do is watch that Wheres My Amended Return website to see when it makes its way through processing.  Again, it can take months before you get the refund from an amended return and they only send a refund check, they don't do direct deposit..