I am feeling a bit down in the dumps, and could use some impartial advice. I've had my new horse for 5 months now, and all has been going well. Apart a few minor issues early on, he has been a laid back and easy going horse. However last week, we were out hacking with one other horse. On the way back we decided to have a canter, and the other horse went off a bit quick. Mine just exploded, massive bucking fit, and needless to say I went flying. The next thing I knew I got up, looked around, and realised I had no idea where I was or how to get back to the stables.
To cut a long story short, an ambulance was called, and I was told it was mild concussion, and I'd be fine in a day or two. It has really shaken me up, and I am not sure where to go from here. I feel like a complete wimp, as you hear so many stories, on here and elsewhere, about people having horrendous accidents, and carrying on afterwards, when I have gone all wobbly after a minor bump. 
Maybe I just need a kick up the backside, and to just get on with it, but I don't want a repeat of the same thing, and I'm not sure how to stop it happening again. I have recently changed my saddle, and upped his feed, both of which could have caused this, or this could just be him getting fit, and full of it. So any suggestions about what to do now would be much appreciated! Thanks!