I never had a problem and could last for hours and even multiple times, that is, until I was about 24-25 and my partner at the time started cheating on me with some losser. I started to lose interest. I moved on and found a new partner only to be cheated on again and again. It got to a point I thought it was me and decided to just stay away from being hurt again so after my partner left, I stopped altogether and would stay way from any situation that could lead to any intimate situation for 11 years. After 11 years, I met a wonderful woman a little older than me, but we were not intimate for the first 3 years of our relationship . When we started becoming intimate, I noticed things had only gotten worse. There have only been a couple of times in 2 years of being intimate with each other that were mind-blowing . But honestly, nothing has gotten better and only lasts 30 to 40 seconds these days. I’m 40 now, and I’m losing interest again. I just feel so useless. I want to be one with my partner but feel it might be a lost cause 
. It is so upsetting and frustrating that I can’t pleasure my partner. I have tried so many techniques, including box breathing, meditation, kegal exercises, meditation, talking to my partner, and even medical advice, even working on my mental health, but ultimately, nothing has worked. I’m lost now and only see darkness in my future.
Maybe tome to seek some medical checks? Seems like you’ve tried the usual stuff. I hope you find your way.
Praying for your success mate keep using this app everyday helps and try supplements if you haven’t already
I wonder if deep down now you link intimacy and sexual pleasure with breakup, pain and loss and grief basically … body saying let’s not go there again sub consciously.
One thing not in your list is in person therapy - maybe worth a try - to help you find some light again.
It sounds like a rough series of relationships and I can see why you might. not want to go there….forgive yourself.
All the best
You must shift your mindset and challenge the way you see women. Focusing on satisfying a woman is against masculine energy and counter productive. Instead you should be focusing on your mission starting today. Improve your diet, fitness, fashion and style, grooming, financial position, work and focus on yourself, take risks and challenges yourself. See women are a reward for your success and do things that please you. Make your life about fulfilling your desires not others.