If you are still looking for a trainer, I would check around and see if any in your area specialize in adult beginners. I don't know where you are, but a lot of farms in my area teach only children at a beginner level and may have one or two classes for more advanced adults. It would be really beneficial to you to have an instructor who has worked with adult beginners in the past. (I am assuming that you would still be in the beginning stages, from your description.) I think private lessons are the way to go especially when you will be just starting out again. My adult beginners spend the first couple of lessons just getting comfortable on the horse, gaining confidence while working on basic balance and posture, and then putting that together with basic control, steering, etc. when they appear relaxed. I also make them put in some time on the ground, leading, moving the horse around, and so on. A good trainer will be able to assess you comfort level and give you tools to put yourself at ease before challenging you too much.
I think it's wonderful that you want to get back into riding! It is great for exercise and stress relief! Good luck, and I look forward to hearing how it goes!
"Keep a leg on each side and your mind in the middle"