well, i don't know if i have any perfect suggestions. if it is too much to bear, maybe you could see a doc or i think Mexico has pretty relaxed policies so you could go and get a prescription of some sort, to take before your appointment.
i don't think pills are always the answer and they are often not the best answer, but i also know something like Valium can work well in situations like that. it doesn't make the pain go away, it is there, but the medication affects you in a way so you just don't really care about it like you did.
i don't even feel too comfortable with this idea, but i guess it could be helpful.