I can relate to your story as I am a 43 yr old beginner taking english riding lessons. I am relying on my trainer at this point to help me select a horse that will be a good fit for me and my family (my children also want to start lessons).
I think you should find an experienced horse person/friend or trusted trainer and let them guide you in your decision. I think you can find a horse that is trained well enough for you to have confidence (not be afraid of it), but still be fun and challenging as you learn. Good Luck!