I'm so sorry you are having to deal with this. I have been in very similiar situations with my current boyfriend, about him lying about stuff that happened before we met, but it is still lying and of course it makes you worry about what else they lie about. I, like you, am a very honest person and I don't understand our signficant other's cannot be the same.

I wish I could give you advice to help you get through this, but I honestly haven't figured out how to get past it myself, so I don't know how much advice I can give Just know that I know how you feel, and I hope your boyfriend is more honest with you in the future.