OCD, tourette. Find good psychiatrist, the one that devotes a lot of times for each visit and doe not hurry you out, one that consciously follow up with response to therapy-medications and adjust meds gradually compared to ones that keep your meds from month to month. Migraine can be consequence from the pain of OCD (which is part of bigger entity of anxiety disorder). Need be very very very patient. Add yoga ++.
Maybe. This depends on the psychologist and their training and experience. Ocd is an anxiety disorder and can usually be diagnosed by a good psychologist. Tourette syndrome is a brain based neurological disorder and this diagnosis should be confirmed by a physician with experience and proper training such as a neurologist or developmental specialist. Proper treatment requires diagnosis in any problem.
Yes. Yes, a doctoral level psychologist can diagnose those disorders.
Limbic vs motor. Ocd is an anxiety disorder characterized by unreasonable thoughts and fears (obsessions) that lead to repetitive behaviors (compulsions). Tourette syndrome is a neurological disorder that starts in childhood. It involves unusual repetitive movements or unwanted sounds that can't be controlled (tics). Ocd can complicate tourette's and vice versa. They may share an unknow common neuronal basis?
Somewhat alike. Both were thought to be closely related due to the anxiety and compulsions related to both but we are now rethinking this. Ocd usually more cognitive while tourette more motor but there's overlap.