Hi, thanks for your query. As you may be aware that recent research has time & again shown that alcohol increases sexual desires but impairs quality of penile erection, time of ejaculation, sexual pleasure & overall sexual performance. These effects of alcohol are directly related to amount of alcohol & number of years of alcohol consumption. Similarly smoking tobacco impairs quality of erection & hence both of these are best avoided in those facing sexual problems. Additionally diabetes if poorly controlled alters blood vessel thickness, penile blood flow & impairs sexual performance. As you are having all 3 problems simultaneously hence to improve your sexual performance start by abstaining from tobacco & alcohol. Then incorporate 30 minutes per day & 5 days in a week exercise regimen of resistance training plus cardio to improve your blood sugar (glycemic) control & physical health. Both of these will help to improve your sexual performance. You can also consult your doctor for utility of medications like tadalafil for you depending upon your physical health & any associated health conditions which help improve penile erection. Lastly do check out Master & Johnson s phases of human sexual response cycle & techniques of non genital sensate focus to improve sexual performance. Good Luck