Premature ejaculation could be a very embarassing problem that you may be handling with - keep in mind that you don't have to be embarassed about it because it's kinda something normal and most of the guys do have it, I mean, not the majority, but you have to learn to control it because you're not going to get any closer to something long term if you just stress yourself out to much. It's well known that young guys may not have the experience and because of it they tend to have psychological problems and whatsoever. 

   Psychological stress is a very important issue and you have to deal with it - if you're just stressed out and you don't know what you are doing, then you may have some little chances of getting the facts that you really want.

   The fact is real and is that 20%-50% of the couples (young couples tend to have this problem) about premature ejaculation and the fact is kinda real. The fact is that if you're young (15-17 years old) and you haven't start your sexual life yet, then it would be having some problems about it. Don't get embarassed about this because you're both going to be disspointed because of it - if you're lasting longer than 5, 6 minutes, then you may be on track and you don't have to worry to much about it. As you may already know, masturbation does not have any reason to make you some sort of premature ejaculation problems - there are some studies that say that a normal couple is going to have an ejaculation after ~8 minutes, so you may not have to worry about to much because of it. The fact is that premature ejaculation guys are going to ejaculate in ~2 minutes, which is not a good thing if you consider me.

   There are some psychological implications with it, mainly with young guys - this is because they don't have the experience and their body and penis muscles are not learn to play with the stres - all you have to do, if you really want to learn this, is to get to learn your muscles and your mind to control the ejaculation and just before you ejaculate to think on something else. I know that the desire is going bad, but the fact is that you won't be able to make something about it, if you're not going to control yourself - there are some courses and practices for ejaculation training and control, but in that case you need to consider many facts and understand that the psychology behind it is very important for a success.

   Don't worry - it's fine for now. It does not matter how old you are, you could be in your middle ages and have this problem, but you could cure it - there are a lot of vitamins and stuff that could really help you with it. Also, a good condom or more are going to help you not to ejaculate so fast. 

   Chinese medicine and plants (herbals) are very good in order to help you get rid of all your problems - you may want to try it and see what's working and what's not. You could increase sperm count volume using ginseng and other chines herbals.