Update. I finally got emails to send from my private domain...
I went back to the smarthost idea and set it up the same as before only this time I used gmail's other port. (number 587 I think it is) Now emails send with no problem from my php scripts. The only issue, however, is that emails appear to be written by the gmail account that I send through. as long as I set the "Reply-to: " header to an account on my domain it isn't a problem when the recipient replies to the message. Communication is working now, it just isn't exactly how I wanted it to work and look.