I am sorry you had a hard time after your accident.  There is nothing to be ashamed about being scared of falling off again.  I worry a lot about that too, it inspires me to keep my heels down!  I also ride a lot at the walk, there is little chance of falling off at that gait (though I did manage to once.)  Heads up, hearts up, hands down, heels down, good advice decades ago, good advice now.

With my MS, before I mount a new horse, I explain (verbally and with mental pictures) exactly how I am handicapped, how it affects my riding, how it makes me afraid, what I have problems with in my riding, and with a promise that I will do EVERYTHING possible (including falling off) not to hurt the horse in any way.  I ask them to take care of me.  Two of the Arabs I've ridden in the past 5 or so years HAVE gone out of their way to take care of me, including a sloooow motion shy across half the ring when dogs exploded out of the bushes, with Glow,a Russian bred Arab gelding, slowing his shy down just enough so my legs could keep me on.  Mick, the Arab gelding I am on now is not as considerate, but I think he has a back problem.  Mia, the bay mare, is wonderful, when she is pissed off at me she gives me fair warning, plus when she startles (except for snakes) she tends to freeze in place first instead of shying.  She will dance around if she thinks there is a snake around.

In the 1930's or so Van Vleet Arabians in Colorado had imported some Arabs from Egypt.  They were doing a cattle drive with the usual remudas.  Mr. Van Vleet told his son that he had to ride *Zarife, an Egyptian Arab stallion that day or he would not be allowed to ride at all.  Under protest his son rode *Zarife and half way through the day realized he was still on the same horse he started on instead of being on his third or fourth horse of the day.  He rode *Zarife all day, and was a convert to the Arab from that day forward.  He had never ridden a horse that had that much endurance before.

Mia, the bay Arab mare, is probably in her early thirties and has problems with arthritis.  She was soooo weak and unsteady when I started riding her (I have a much earlier blog "Rehabilitating Mia"), but when Debbie asked me to start riding her my thought process was--pure Arab mare, obviously descended from war mares, I just could not refuse even if she was most likely permamently lame.  I feel honored every time I ride her.  To me the highest created being on Earth is the Arab mare!!!

You know, you can work on this gradually.

There is nothing wrong in getting up and just sitting on a standing horse.  According to Udo Burger ("The Way to Perfect Horsemanship" READ THIS BOOK) this is a wonderful exercise for the horse, giving the horse time to adjust carrying your weight without having to move.  Even just standing there you are giving her back muscles a chance to get stronger.  After a week of just sitting on her for maybe 10 or 15 minutes a day both of you may feel a lot more confident, her because you have given her a chance to learn how to adjust to your weight without any other distractions (like moving), and for you because you will feel like she is more confident carrying you.

When my first horse, an Anglo-Arab, dumped me he would usually just stand there sort of snickering, sort of saying that I was supposed to STAY ON his back, what in the world was I doing down on the ground?  The first time I fell off this horse I had a concussion, lost consciousness and was out for three-four hours?  I was not allowed to ride for 6 weeks, a lot better than 9 years I know.  The riding stable put me on a 29 year old ex-cow pony, one that would move himself under a rider starting to slip off, and told me that the horse would have a connption fit if I fell off, nobody fell off that ex-cow pony! 

I rode my horse for many many more years, Hat Tricks, my Anglo-Arab, was an angel from heaven.  It was not his fault I fell off then and got concussed.  By the way, as wonderful as Hat Tricks was he never came back to check on me, he just stopped until I got up and got the reins. 

It sure sounds like Mora would enjoy you just sitting on her for a while.  It would not hurt to try.  You have a war mare there, she came back to guard you.  Tell her your fear, ask her to help you work through it, tell her you cannot do it without her.  I bet she'll respond.

You did exactly what I was going to suggest, taking your time with each step of mounting.  Going SLOW can solve a lot of fear problems for both horse and rider.