Need help getting card....

Hi everyone, I'm a 61 yr old pothead from Alamogordo, New Mexico, and I need some help getting my card! I've been okayed by my primary, but because I have chronic pain issues, I have to have another doctor sign off on my condition! The main problem is I've been on SSDI for 10+ years and haven't seen any other doctors for my pain. There's doctors (who advertize) that will sign off for me, if I travel 250 miles and pay for an exam, but the cost is prohibitive to me. As I said I'm on disability and live on a fixed income, and to have to pay a couple of hundred bucks for a card that's free, is totally wrong!! Is there some way to get around this "Extra Cost", there should be a doctor in Las Cruces ....but how do I find one? You'd think after being treated for chronic pain for 10 years, that would be enough proof........somebody help me, please!!