Henry,

Welcome to NeuroTalk.

With the symptoms you mention, it does not sound like your trip would be such a good idea. A foreign country is a bad place to have an increase of symptoms. I don't think the trip would cause damage but could greatly extend your recovery time. I wonder how you could enjoy the trip with your symptoms.

I am confused, other than your cluster of symptoms that can be related to a concussion, why do think they are ? You say you did not suffer any trauma. Have you had a concussion previously ? Have you been in a whiplash accident ?
Have you been ill ?