I'm 45 and I held on to a horse for three years. The horse was a good horse but he has a spooking issue. I couldn't get to where I wanted to be with riding because of it either. I wouldn't say it was ego that kept this going but pressure from really good riders who would say this is a great horse do this or do that. I finally have had enough and put him up for sale. I also worry that he will go to someone who can't ride him and will end up as one of those horses that get passed around.
The one thing I've noticed about owning a horse is experienced riders seem to forget when they started out and knew nothing. Just my opinion