First of all, congratulations! You have earned a spot in the most prestigious footrace on Earth. Most people will go their entire lives without ever having completed a marathon. Of those that do, many never will without walking. A majority will never even come within an hour of their Boston qualifying time. The fact that you are in Boston at all puts you among running's elite.
Every time you didn't hit snooze after only four hours of sleep, every time you looked out the window, saw rain, and laced up your shoes anyway, every time you passed on a late-night party in order to wake up early for training the next morning, I hope you already feel like it was worth it. In a way, those are your real accomplishments.
I'm not running Boston this year, and due to the travel expense, it's possible I never will again. And that's OK. Boston was an experience I'll never forget. As much as I've fallen in love with trail running, Boston remains my single favorite marathon experience. The 1 million fans, the history, the prestige, the Wellesley Scream Tunnel. Heartbreak Hill. Fenway Park. And the buzz that seems to captivate the entire city on race weekend (not to mention it's incredibly well-organized, even without considering its considerable size. I'm looking right at you, LA). Every good runner should run Boston once, if they earn the chance. And I'd love it if more runners achieved that honor.
Most of all, good luck, run hard, and enjoy it!