The card is only valid in new mexico.
You can purchase as often the have product there is a limit of what you can have in your possesion.
Go here and this will give you all the infor you need and the applications.
Medical Cannabis Program - Infectious Disease Bureau

It takes as long as it takes for a doctor or in your case probably 2 due to chronic pain catagry which is what i personally fall under i have all the same symptoms as you except my headache is extremely severe all day everyday non stop for the past two plus years. It took me a while because i had to convinse my doctors i wasnt full of shit. Finding a doctor will be your hardest battle i think.
You dont have to have insurance but you will just have to pay out of pocket for your doctor appointments. Realistcaly any doctor or nurse practionar with the abilty to write a prescription is able to sign off on the paper work but alot of doctors i think are unaware or just not a supporter. Welcome to the battle it doesnt stop after you get the card.