The Scottish star acted and produced the new action thriller and revealed the pressure forced him to travel the globe as a way to relax once filming ended.
He told DigitalJournal.com: "I've been making 'Olympus' for a long time, so I thought it was time for a break. I decided to travel.
"In the past six or seven weeks, I have been to Scotland, England, Italy, Switzerland, Thailand, Mexico, Columbia - all for different reasons.
"But, mostly for travelling, just going to places and seeing friends... But, the real highlight for me was in Thailand, becoming a monk. I was hiding out in temples a lot."
Gerard, 44, admitted combining roles both in front of and behind the camera was "tough" and he went "insane" trying to balance them.
He said: "I have to tell you that sometimes, when you are producing and you feel that weight, it's tough.
"A couple of people were reminding me while we were in the middle of making it of how crazy I got.
They would tell me about how insane I got and things I was saying. I would go, 'Oh yeah, so I did.' "