First of all, I am highly suspicious of the diagnosis of transverse ligament injury. This is very rare and normally, the odontoid process fractures before the ligament tears. You could however have developed injury to the facet capsules of C2-3 and C3-4. This is much more common and much easier to treat.
Craniosacral therapy is a chiropractic term but has now been adopted by the physical therapy as well as massage community. As long as there are no ballistic maneuvers (high-velocity manipulation), if this therapy helps you, wonderful.
If no manual therapies are helpful, you could consider a consultation with an injection interventionist. You might undergo facet blocks at those two levels. You must keep a pain diary (see website). If you obtain great temporary results, you could consider a rhizotomy.