Alot of wonderful advice up there. I totally agree to do not let anyone push you beyond your comfort zone. Also the key to falling is to roll.
I had my confidence shattered when I was in my late 30's by my 16.2 knothead TB. I realized then I no longer bounced, but thankfully my sub-conscience would kick in and take over where I still rolled when being tossed.
My lack of confidence carried over to my young QH, who was newly under saddle, which wasn't a good thing. In my mind, she could blow up at any time. It took time to get my confidence back, which just blew my mind as I've ridden all my life, hit the ground before many times over many years, and was still next to fearless. We become more cautious as we get older.
My confidence came back, as will yours. I'm 50 now and do excercise caution. I ride my own horse as I've had this one all her life and trust her. I won't climb on froggy horses anymore - I think "what if I come off, land wrong and break a hip?" lol.. I'm old now.
You work at your own pace. Just tell your trainer what the deal is straight up. She will have to deal with it and comply with not pushing you past your comfort zone, period... like it or not.