What legal steps can I take to expunge my felony conviction? Criminal Records, Expungement

So, I was moving from CA to TX, and I feel asleep behind the wheel. I was arrested for a DWI and possession of cocaine and marijuana. I ended sitting in jail in Phoenix for about 2-1/2 weeks, and when I was released, I made my way to TX. I could not afford to travel back to AZ for my court case, let alone afford a lawyer to defend me. So I believe I was charged with possession; 2 counts and the DWI, although I am pretty sure the DWI results were inconclusive. And I have the two warrants I think for failure to appear for the court case. Being that this was my first time offense, I am wondering what I would need to do to try and get the felonies expunged off of my record? They are prohibiting me from getting a decent job and after my parents payed for my college education, I feel like the rest of my life I will be wasting my degree away, due to my stupid mistake. I would need to find the most inexpensive way to handle this as well, due to our crappy economy and me not being able to get a job here in TX, due to all of the background checks that even the crappiest of jobs are requirig, I am very short on funds. Any and all help/advice, would be greatly appreciated.

Cheers and good luck to all!