As a Perinatal nurse, lactation specialist and mother of 4, I understand what you're going through. While I was nursing my 2nd child, I ruptured 2 discs in my neck and the pain was incredible. (The rupture was due to an injury 10 years prior to the rupture). I went through months of PT, pain meds, traction, braces with varying relief for 7 years. Finally, I went to a rolfer and it cleared up for good. I found a rolfer who was also a PT so it was covered by insurance.
I am constantly telling moms to get themselves comfortable and in a good position and then have someone give them the baby to nurse. Always bring the baby to you - don't lean to get to the baby. Use as many supports as you need to help get the baby in a good position - pillows, chair arms, your legs (sitting in a bed with knees bent up helps support the baby on your legs, takes the weight off your arms ), use a stool to support your legs up if you are sitting in a chair. I know it's usually not practical to have someone there to hand you the baby after you're comfortable - so always try to get yourself in good position before attempting to nurse.
I don't know if you can find a PT to help with positioning or work with a lacatation specialist. Your pediatrician would be the place to ask about that or call the unit where you delivered and ask the nurses for recommendations. They are generally more up on that than the doctors.
Good luck and I hope it get's better fast - it is so depressing having pain and it can make a person grouchy.