Jeepers! Sounds like you have been through it! I understand where you are coming from...
I started riding briefly last year - I had a couple of lessons of walk and steer etc - then I had to go full time at work for a few months over winter so it wasn't really possible.
I went back in february - did loads of trotting, various exercises to improve, went out on walking trotting hacks, started to learn to canter. Some horses were easier than others - some would try to stuff their wee faces en route, some had a stumpy trot, some had a floaty trot, and one would freak out and suddenly do this sideways leap at imaginary lions in the hedge.
My heart would sink or leap accordingly as to which horse was mine, but I always took it as a learning experience.
About 12 weeks ago we went out on a group hack. I was riding a horse I hadnt ridden before, although I'd seen him being ridden by other members of my group. We were in a steady walk around the edge of a field when he suddenly stumbled and his entire front end went down and I was thrown off. It seemed to last forever that fall - it was very fast but also in slow motion? I thought I had given him a heart attack and that I had killed him and that he was going to roll on me.
I landed on my back at a bit of an angle and rolled away. It seemed like it lasted forever!
I looked at him, and he had got to his feet and was cropping the grass - the pain was deep in my lower back and wasn't too bad, so my instructor checked me over, I got up and dusted myself down and we rode back.
I got home and was in quite a bit of pain so I went to A&E and I had a fractured coccyx which was displaced and now my coccyx points to the right.
I was really lucky and my coccyx healed really quickly - I went back riding a few weeks later on a very floaty horse just for 30 mins at a time.
But I have lost my confidence. I ve been out on a couple of hacks since and every time the horse kicks up a stone or misplaces a foot slightly my heart races and I think I'm going to fall off.
Today I had a group lesson and was on the horse with the sideways leap. It was very muddy and wet with a bit of a puddle at the bottom of the school - I was coaxing her forwards through the puddle on the track and either she tried to jump the puddle or tried to buck me off - am not sure - but my nerves were shot!
We got into canter but she didn't seem right and it felt like a battle to contain her trot normally - without going into sitting trot, placing legs, feeling confident, keeping her on track etc - she was snatching the reins and was quite hard work.
I think that's cos I'm a crap rider - but I'm struggling a bit at the moment, so know where you are coming from. Although you sound like a really good rider!
I have just lost my confidence - I still enjoy it - but am much more afraid!