I responded in your other thread, but wanted to add some thoughts here specifically on your confidence.
First, there are so many “new” safety options these days. Get them! I ride wearing a MIPS helmet, a Hit Air vest, and Tech Venice safety stirrups. My confidence is good these days but I’m pretty sure it would plummet if I didn’t have my air vest and MIPS helmet. Back when my confidence was still recovering, I wore a Tipperary under my air vest. All of these are good to have from a safety standpoint, but don’t discount what they can do for your CONFIDENCE.
Second, and relatedly, take advantage of whatever calming supplement works for you and your horse. There is NO SHAME in using either, whether it be temporary to get you through a rough patch or permanent. SAFETY FIRST is the rule. Feel free to double up on some of the calming supps for your horse. I really like SynChill and use it before rides when I think it’s a good idea for safety reasons (usually cold windy days because I only ride outside). But you could also put him on a daily magnesium supplement in addition to SynChill. I like SmartCalm Ultra myself. I know some people will give you (or me) a hard time about this but if the alternative is to stop riding, I know what my choice is. And yes, there are calming supplements for humans, too. Rescue Remedy is a good one but there are others.
Third, work on your own riding fitness off the saddle. I really like the Rider Pilates Club. I feel so much more stable and secure in the saddle these days than I ever have before, even back when I was doing lots of yoga and Pilates and technically in better shape than I am today.
Fourth, find a confidence builder to ride! It doesn’t need to be fancy or well trained or anything other than a solid citizen. Spend some time doing walk trot only. Be okay with it being a dinky trot. Do some longe lessons on a horse that is good on the longe. (Try to find a vaulting coach who will give you longe lessons! I did this and it was amazing! Those horses are PERFECT on the longe.) When you feel mostly up to it - because you might not ever feel completely up to it - canter on a horse with an easy canter. Do it on the longe the first time if that is what you need. Come over to my place and I’ll let you canter on my gelding. I joke that everyone should learn to canter on a horse like him because it’s so smooth, effortless, and easy. He makes you feel like you’re ready for the Olympics. Maybe for you it’s a nice, older QH with a canter that is really flat. Whatever it is, take baby steps! Each time you do something “new,” your reaction should be smiles and laughter and FUN, not fear. That’s how you know you are ready for that new step.
Fifth, give yourself TIME to recover your confidence. It took a while to lose it and it’s going to take a while to get it back. That’s okay. There’s no timeline you need to follow other than your own comfort level.
I don’t know if your horse is the right horse for you, but all of these things will help you, regardless of whether you keep him or not. I really wish you the best of luck. I had a bad fall a number of years ago and my confidence definitely took a hit. (See comment re air vest above - it seriously is my security blanket.) But I am doing totally fine now. And you can get there, too.