Aw, so sorry for your rejection! That stinks. Yes, totally wallow, wallowing works. Have lots of junk food and candy! As for the comments on your plot, if you really love the book, I wouldn't put it away just yet - try tweaking it a bit - and if you're done with it, shove it under the bed, you might have more clarity later on after having not looked at it for a while.
I just got a reject on my full, too - so I know how it stinks. Good luck with your writing and future submissions! Getting an offer to look at your next project is really good! That means the agent likes you enough to look foward to something else - I've never had an agent tell me that before! Chin up! Keep trucking! Keep writing!
Good luck!