I got started climbing mostly coconut palms with spikes. Not uncommon to find yourself at 60-70', in 10-20 mph trade winds, tied in at about 5 in diameter. Those babies can swing 8-12 feet off center pretty easily. I was scared all the time, but fortunately if you're good with a cane knife you only need to be up there about ten min or so before the work is done. I used to focus on my breathing, work a mantra ("I am a part of this cycle"), and zone in only on the work to do and get the hell out.
I've been in Oregon for about 4 years now, learning tons and growing lots. X2 on studying biomechanics and familiarizing yourself with species etc. also sharing the loads between multiple TIPs and rigging points is major, and using multiple ropes/climbing systems is huge for me.
Sounds like your foreman is a dick. Don't let him rush you, and if he is, go beyond him to his superior to discuss the serious safety concerns involved with a leader who values production over humans.
For what it's worth, when we visit in laws in HI, I am quite fearful of coconuts, including/especially some that I have climbed previously, often many times.
Some one once told me that being afraid isn't reason enough not to do something you want to do.
Nausea sounds like breath management might help, slow belly breaths. Cool thread