Occipital Neuralgia, TMJ, Myofacial Pain Dysfunction

Hello, I have just recently  been diagnosed with Occipital Neuralgia and TMJ. I have chronic pain 24/7. Finally a doctor has worked out why I have these severe headaches all the time and is trying to treat me. So far I have had meds prescribed, Rivotril  (Clonazapam) and Neurontin (Gabapentin) which I can only take at night because I can't function in the day due to the drowsy effects, and I take Ibubrofen and codeine 2 x 2 every day. I have also had cortisone and anesthetic injections which didn't help at all.
Do you think and osteopath could help my problem? I am feeling rather desperate here. What other suggestions could you make? I am 47 yo and have had headaches since I was a teenager and over the past 15 years they have been much worse.
Thanks in advance.