Talk to Sexologist on Erectile Dysfunction

Hope everyone is fine. I have a problem since 7 or 8 years, i used to do excessive masturbation, due to which 8 years ago i felt like i am having erectile dysfunction . Now i am going to get married , and i cant get erection without viagra or any erection pill. My penis is also tilted towards left side. Do not have the strength to keep erection for more than 20 seconds. Really worried and hopeless as everyone in my friends say that this is laa ilaaj. Once an Ed is always an ED. Its not psychological issue, it seems like i have damaged nerves and tissues in penis. Kindly if someone can guide me