Firstly, let me commend you for thinking of the girl's feelings and not wanting to offend her. Keep that in mind all the time, as it makes you exactly the type of guy that girls want to meet!
Never, ever worry about it being horrible! Everyone is nervous about this, both guys and girls. Girls are always flattered that they are wanted. But neither do you have to make the first move. Girls often make the first move, and they do that when they feel secure, respected, and know that the guy is genuinely crazy about them. Instead, when things start to get heated, be more concerned about exploring her, talking to her, letting her know that you're wanting to please her, etc., and she'll guide you.
I would stop to ask you, however: why are you so concerned about losing your virginity? Is it just a strong desire to have sex? If that's the case, that's perfectly natural, and don't let anybody criticize you for it! Wanting to have a healthy sex life is an important and worthy objective in a balanced lifestyle.
However, I always worry about people having a healthy first-time sexual experience, as it sets the pattern for the rest of their lives. I'm sure you want this to be memorable, so that you can look back on this later in life and know that you and the girl both think of it as a great time. The best way to achieve that is to first let go of your feeling of needing to rush into this, and instead worry about meeting the right girl to share this experience.
To do that, you need to get out there, meet and date regularly, take good care to make yourself attractive, etc. If you exude good, happy vibes, and let yourself be emotionally open, then she'll walk into your life, *guaranteed*. Everything else will flow naturally.
Remember: great sex can never be forced - it only happens when the right people connect for the right reasons.