Can any online doctor tell me the remedy for premature ejaculation ?

sir I am a male 21 years old. I am masturbating from past 8 years (sometimes up to even 4-5 times a day as well) and still a virgin. sir I am suffering from the problem of premature ejaculation . whenever I masturbate, I usually have a fall within 10 seconds. although in past i used to hold up to 3-4 minutes as well. I am really depressed from my weak sexual performance and it is getting worse day by day. besides I also have the problem of underdeveloped penis. although length is about 5.5 but girth is quite less. and neither i get harder erections. Any doctor or any other person who can help me,please tell whether there is any way to come out of this problem and most importantly from premature ejaculation. I will be thankful to you forever.