I Am Having PM Problem. I Have Been Married For

I am having PM problem. I have been married for the last 4 years. From my early childhood, when I as only 13, I started Masturbation and still continuing with this practice. Initially the frequency was 6/7 times a week for 7/8 years, and then at a reduced rate of 2/3 times per week. During my early childhood, my erection is very good, strong and around 20 degrre upward directed....Now, it has gone down....my penis base has got narrowed down and it feels soft even when it is erected, the angle of erection is 10 degree downward directed...the most frustrating thins is that I cannot stay more than a minute after penetration.
Could you please advise?