I agree with all that has been said. Do consult a physician, but I'm pretty sure what you're going through is normal. Nothing wrong in taking a pill for confidence reasons... personally when I know I'm a little slower I'll take 1/4 viagra with water about 20-30 minutes before. Its enough for me to last the entire night. Sometimes, I'll go as far as 1/2. I personally found Cialis to keep me in a strange haze longer. It didn't suit me well. Again talk to a doctor.
As you get older you'll come to understand how normal it is for it to happen from time to time. Stress, foods, less physical exercise, not drinking enough water etc. and it fucking sucks balls. When I got divorced and was single for a while, I increased my masturbation... bad move.
The problem with frequent porn and jerking off is it will not only desensitise your dick (death grip) and make it harder for a woman to get you off; but frequent use of porn also desensitise the actual sexual routine in your mind. If you get used to ejaculating within 2-3 minutes between initial arousal and orgasm by staring at a porn goddess... you can imagine how out of shape you will be with a real/normal woman.
Limit how often you jerk off. Try not to use porn if you can but If you do need to watch porn, don't skip thru, don't jump from scene to scene. That shit will fuck up your brain in going straight for the arousal points... talk about self de-programming.
Its like training for speed when instead you need to train for endurance. And each time you fail will make it more and more difficult. The psychological impacts are a disaster for performance in men.
Talk to a doctor but pretty sure he'll tell you to eat healthy, do some exercise, don't smoke., don't do drugs lol
Quick Note:
out of curiosity, when watching porn, do you watch more oral scenes or fucking when you cum or neither?