I am 37 years old and I have no trouble getting an erection during masturbation or foreplay. I can get really hard. However during sex I cannot maintain a really hard erection as I do during foreplay and masturbation. At some point I feel getting softer. And if I attempt to stop, to change position or because penis was accidentally removed my erection is easily lost and without removing the condom it is hard to get it back.Also when i watch porn i don't have the erection problem erection remain for 3,4 hours till i masturbate ,but during sex with my wife i loose erection .
I am really confused cause I know there is nothing wrong with me physically and mentally. I am a relaxed type of guy. no worries. i enjoy my life. I dont understand this.
Any advice and help is welcomed.