I am from Texas and I had to amend my return (adding another form) so where do I send it to since I can't e-file?

Here's the instructions for 1040X Amended return.  Where to file on page 18

http://www.irs.gov/pub/irs-pdf/i1040x.pdf 

For the address to send your federal amended return, please see "Where To File" on page 18 of the Instructions for Form 1040X..