Before I edited the file, it showed a FROM email address (no name, just an email, but that was fine), but then after I edited the labels, ids, etc., it no longer showed anything in the FROM. But I found out what was causing it. I had changed input name="Email_address" and id="Email_address", etc, in every instance on the contact page, to just one word "Email" in every instance that it appeared on the contact page. Apparently, there must be some other place/page where it needs it to remain "Email_address" because when I changed it back, it worked again.
It's working now, so I'm not going to leave it alone, but for future reference, what other files are dependent on these names. I am thinking that if I could find the other code that depends on the name, I could change it consistently everywhere it referrs to it, so then it would work.