There are a couple more TDRL posts on here that could be helpful including CRSC for TDRL vet - so confusing!.

The other thing to keep in mind when figuring out CRSC, is the documentation part. What those folks are looking for is anything that links your disability to a combat-related event. For PTSD, you may have it in the narrative summary of your VA rating. Anything that says "had PTSD due to event A and event B in combat" would do it. Notes from the physician that did your eval, any "official documentation" that will say what caused it. "Servicemember has nightmares or can not concentrate because of PTSD" would point out a symptom, but not the cause, so look through your documentation. MEB is usually more detailed and will probably have the right stuff to back up the claim....