Quote from Bloom3: you sound like a good guy jess. just keep talking to her. i bet she'll understand and is feeling some of the same feelings about not wanting to disappoint you too.

This is a two-way street and, other than subjects that might cause obvious jealousy issues (hot chicks) I wouldn't worry about appearing to be perfect. Oh, God, please don't be perfect! If you start withholding stuff from her, I guarantee she will resent that more than anything else about the decision to take your relationship to the next level. If she is half the person you are, she values your friendship over and above the romance. Whether or not she lost her virginity to you, over time she'll even value that, whether you remain together or not. Who better than her best friend?