All of your sense are so focused on her and how it feels and the novelty of doing it that you become carried away. This is really quite natural and of course works and was designed that way to insure reproduction. What you need to learn to do is take it easy. This often comes from experience, but their are things you can do. First of all calming your mind. She feels really great so you get so into thinking about that you come really fast. If you can calm your mind by thinking about other non-sexual things that can help. Meanwhile feeling her would be enough to keep you up there and going but you think of other things so you are not carried away by your excitement and arousal. This is what a lot of men teach themselves to do. Then with experience they learn this way to last longer and longer and longer. Also with experience the feeling becomes less of a novelty - you get more used to how she feels and it feels so you can naturally go longer. Men learn to control themselves this way and then after it becomes more commonplace for them they are used to it so they have more confidence in what they can do. If she is into you she will wait for you and help you. Most of us like that you are enjoying us and want you to because it makes us feel good but then we also want to feel good ourselves which often does take time for us to get hot and up there. You might try bringing her off with tongue and/or fingers so she will become used to responding to you. Then after her orgasm or orgasms you can start intercourse and this is a way of making it good for both of you while you are adjusting to one another and you are learning to keep going longer. A lot of young men tend to go too fast anyway perhaps because they have seen it in porn and a lot of us really need slow steady gentle movement over a long period of time. rather than just fast and short bursts of energy like you are trying to get it over with as soon as possible.