Congrats on giving climbing a try. I agree pictures would be nice, if you are doing something way out of whack you should be scared. If not, give it time and do it often. Use your own gear when you get it, and learn it inside and out, keep your ears open when talking to people that know their sh1t, one little tip could save you.
Heights never bothered me, as long as what I am working in has the strength, nothing like being way up on a small dead branch, or rigging big stuff from a tall canopy. Its a risk thing, higher=riskier in those situations.
I would say the cure to your fear will be knowledge. People say "how can you hang from that rope?", you say breaking strength is 6,000lbs, nothing to be scared about. That's why I say know your gear. Also learn to be a good judge of a tree's, or section of a tree's structural integrity. Tree work is all calculated risk, if you don't know your gear or the tree, you can't calculate thus making things scarier to you than they probably are. Also know your physical limitations if you aren't in tip top shape or capable then get out of the tree. In short the components are you, your gear, and the tree. Learn it.
Knowledge goes a long ways, but you still need balls if you want to be a "go to" climber. Anyone can call shots from the ground.
Climbing is nothing like felling trees, but if you can fall trees accurately that is a skill you can take in the tree with you. Good luck.
Oh yeah, if you do get that saw in the tree, make sure there is somebody around with experience, cause it aint the same game as logging, you can run from danger when dropping trees, where are you gonna run to in the tree. You can't get sloppy up there with cuts and I mean that with the utmost seriousness.