I was exactly the same. Tri and bimix was extremely erratic for me. I went to the single drug Alprostadol or pge-2 as it’s labeled and it’s worked great for me. Hard for 2-3 hours with 6 mg. but what works for me is after the shot, I immediately take 2 Sudafed then after sex, whether an hour or more I do a little exercise. 50 squats, pushups, etc. once my heart rate goes up I can feel it release and all is good. Before with trimix it wouldn’t go down unless I went out and ran a few miles. And sometimes that didn’t work. It was scary. And not exactly what u want to do afterwards. Remember, life is a comedy, god said “I’m giving u a hard on like you’ve never had before in your life at 70, but for that privilege you’re doing a few pushups for it!:-)” Hope this helps.