It sounds like you've found something wonderful in your boyfriend. I remember that moment when my fiance and I finally started dating, and feeling the same way.
I remember the first moment that I saw one of my partners with someone else. Even being fully okay with it intellectually, I had to remind myself to take a moment and really think about how I was feeling. Once I took that moment, I knew I was fine. None of the responses society told me to have were there. I was just... pleased. (I'm pretty low on the whole 'jealousy quotient' thing, so my story isn't inherently typical; don't worry if it doesn't fit you at all.)
Just take your time, enjoy each moment as it comes. Store up all the good ones and save them for rainy days. Congratulations, and good luck!
"I was thorough when I looked for you, and I feel justified lying in your arms." - Chasing Amy