Hey Tanya I'm in UT too. I hope you're not flooded. This is crazy.
Anyway, is it your goal to ride? If riding makes you uptight, maybe you don't really want to ride. There's nothing wrong with having horses just to watch, enjoy, pet, brush, etc. If you are happy doing those things, just do those things. Maybe that's all you'll ever want to do, or maybe doing those things will inspire you to ride one day.
If you want to ride, take lessons, find a confident friend to ride with, practice riding a different calmer horse, practice ground work, saddle up and lead the horse around and untack, hang out in your pasture or paddock just spending time with your horse. Set small achieveable goals such as just sitting on the horse's back or riding the perimeter of your pasture or arena, then work up to bigger goals like trotting, going on a trail ride, whatever it is you'd like to accomplish.
Small achievements are achievements!