Premature ejaculation. It will take?

This is Anas. I have addicted of Masturbation since 2000. I don't have any health issue. I am unmarried yet. Expecting to get married end of this year. I am a smoker and smoke 5 to 10 cigarettes in a day. Non drinker. I never intercose yet. I have slept more then 50 times with my girlfriend but never did sex. I feel  hyper sensitivity in my pennis and due to this I early discharged every time. My pennis size also shrink little bit as I noticed this. And hardness also reduce. I stopped Masturbation 1 month ago completely. What I am feeling now, I have less stamina, less testosterone I think less hardness and early discharge due to hyper sensitivity. From last few days I have just started kegal exercise also. Need proper guidance and treatment to overcome from this situation. Please help me to guide me with proper treatment and how long it will take ?