Suggest Treatment For Erectile Dysfunction

Question: Dear Sir,
I am XXXX at 36 yrs, height 6ft, weight 75kgs, unmarried. I am suffering from very poor confidence in erection since my early 20s.
When I was 14 I started a practice of sex with bed means I used to press my penis against bed as if I lie over a woman. As I apply back forth motion my penis erected. I continued such process of apparent having sex against bed until the penis gave the feeling of ejaculation. While performing I used to imagine my women of choice. I continued that practice for 3-4 years. At one stage I became very weak and my urge for the practice of bed sex declined to none.
Several times I took treatment to recover from the feeling of declined sex appeal. During treatment I used to get huge continuous erection and strong desire for practical sex. Such urge during medication becomes so uncontrollable that it remained erected for 2-3 days but I never masturbated again. Once stopped taking medicine my frequency of erection declined gradually day by day. Eventually it seemed to me that my penis is not strong enough to have sex with women. But I have never had practical experiences of sex.
Each time doctors mostly prescribed different variations of A-Z multivitamin tablets for 2-3 months with some additional medicines. I even tried herbal treatment but results were similar means sudden increase in sexual desire for some days then gradually decreases.
At this age I do not feel the courage to get married because I got the feeling that my penis is very small. Even if sometimes my penis erects it ejaculates in 1-2 minutes. Also I get irregular night falls. It might happen twice in a week or may be 3-4 times a month.
Now I have no confidence to undertake marriage because I feel my penis will not erect before a women in bed. Also have suspicion even if it erects it will ejaculate in less than one minute before entering vagina. Also feel it will not get hard enough to be able to insert. I feel as if I am scared about marriage.
I do not even feel the urge to masturbate since my problem started except during medication. Most of the times when my penis gets slightest erection inside underwear it give marks of secreted semen.
I also feel that watching sensitive parts of young beautiful women does not generate strong sexual feeling in me because I do not feel to masturbate after seeing beautiful women.
This problem with erection sustenance is increasing my stress and anxiety which ultimately negatively affecting my desire for erection that is creating a feeling in me that my penis has become too small and too weak.
I did ultra sonogram of penis and testis according to recommendation of a sex specialist the results showed they are normal in size.
Also I did a sex related hormone test according to recommendations of a medicine specialist. Those results were also good.
Would you please suggest probable treatment, including doses and duration, for me to help restore my sexual capability? Is it treatable in Bangladesh?

Best Regards,
XXXXXX