I am in the same boat as you. I have AF and low thyroid, which are doing much better since I started taking Astragalus, Yarrow and Echinecea/golden seal tinctures twice a day.
I never tried Kegel but I do Yoga and that has one posture for pelvic, which helpful.
I have experienced another thing that I am trying to monitor and keep a record of and will need a study from many other men of all different ages and types. Here is what I have found that over hydrating in the morning (with water and juices, 32 to 36 oz)helps my erection a lot. When I am not hydrated well it goes back to normal weak erection. Somehow over hydration makes my bladder push on areas which helps my erections. Now I have only done this for a week. So more to come....