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....

Archus

Arginine isn't the wonder which it was marketed to be, for years.

Agmatine actually does what Arginine was supposed to have been doing, all this time. It does not require loading, but actually should be cycled. No more than three days in a row, with at least one day off. and it takes effect, quickly. 15 minutes or so and your body starts feeling the boost. As such, its a great opportunistic supplement. Take it before sex. take it before exercise. take it before sleep, you will wake up more refreshed and more recovered.

L-Citrulline and Quercetin are synergistic. Studies have shown that men who regularly take Citrulline and Quercetine, have more and/or better quality erections. I find personally, that it works best when taken right before bed, On a regular basis. I take it about 4 or 5 days a week. However, it does seem to increase sensitivity. Which itself, can be a problem for some men.

I use the bulksupplements.com brand for L-Citrulline and Quercetin. I buy from Amazon.com. Citrulline should be L-Citrulline. Not "free form".
For Agmatine, I feel that the "Hard Rhino" brand (Also available on Amazon.com) may be a little more potent. After two bags of that and now a bag of bulksupplements.com's agmatine, I will probably buy Hard Rhino, next time.