Talk to Urologist on Erectile Dysfunction??

Salam, I am un married and 28 years old boy. I am facing Erectile Dysfunction?? issue for long time. I used to watch porn and musturbate in my past but I have left everything from past 2 months. I DONT watch porn now neither I do musturbate but I cant see any Imporvement yet. I need its solution Because I am getting married next year and I dont know whome I should dicuss this issue, can anyone please tell me what to do what tests I should go through to find the real cause? I am smoker too and have been smoking for past 7 years.. I have tried to get rid of it but I am failing again and again due Stress so ?? I am smoking even more. :( Please help or suggest me something..