Currently my head is a melting pot of possibilities on why I struggle to stay hard during sex, it doesn’t happen every tine but seems frequent. I have a new partner of of 2-3 months who I love dearly and attracted to greatly . I’ve noticed on occasion that after a few minutes I get inside my own head and worry about staying hard rather than being present in that moment. This is where the panic sets in! I keep going sometimes visualise porn scenarios trying to maintain an erection. In doing this I think Im taking myself out of the moment due to worry. I had an inguinal hernia operation a few months back and my balls and penis where black and blue from the operation trauma thus worried me at possible lessened feeling when healed and im still trying to figure that out. But could that be a cause of my worries in the back of my head which is causing some panic when Im have sex? Or is it new partner worries? One of which I have huge feelings for and therefore feel more pressure? I’ve explained these things to my partner and she’s understanding of it all which is great however im still getting some issues, im also going to do a testosterone test (im 38) as im not feeling as horny during the day etc as I have been usually. Hopefully this is purely psychological and I will overcome this soon. Be positive kings! 
I also have a new partner that im struggling with. The sex life has been difficult. Not sure if we are just lacking chemistry or if its me in my head.
This has been going on for me for the last 2 years since a major break up. It was a challenging relationship and I chose to leave. Now I am scared of someone else wanting me, it feels like a demand (my former partner was very sexually demanding among other things). Sometimes I can still have the best sex but if i get stuck in my head i lose my erection and sex drive and find jr hard to bounce back. I know its all psychological and fear relates, hopefully i can master this sexual part of it while dealing with the broader fear of intimacy with my therapist
I’m also with a partner who I am strongly attracted to. But for some reason there is this huge disconnect where I just don’t have a strong libido. I know she’s hot, and the sex is hot but my desire is lacking. And so it’s challenging to get hard.
It’s not about knowing, but about sensing it. Touch her, feel her sexiness bodily. Stop thinking. I know I am having the same situations, but the clue is to get out of the head and into body. I’m struggling with keeping it up, no matter how sexy my partner will be, the routine in sex will set in and it will make me see all things boring rather than exciting. Interestingly with other partners who might be less sexy, I can experience less trouble, because they can trigger by other things, like special voice, way of moving, special blink in the eye etc. All this and many other things play a huge role