I am 40 and understand. Could be deca. But someone mentioned psychological. Has u do gear, at our ages, strength comes quickly, sometimes to fast. Our bodies aren't ready for the stress load. I am getting at maybe a pinched nerve. Or a sore muscle that takes the concentration out of the intercourse. Thicker blood like high blood sugar? Not saying diabetes, but maybe a bs of 200-225. We cant break down 150g of carbs like we use to. Two years ago I went through some depression I didn't want to face it. I injected test e 1500 wk in 3 pins. I did this for 4 weeks. Other than a surge in stomach cramps and sweating, it helped the erections no more than the 750 I was on. Even if you are against porn, that can be a good test to test your arousal. Nature can be cruel. Best to you