I think it's extremely different for everyone!
As I was young when I was diagnosed in '06 I accepted it quickly, whether this was due to naivety or otherwise I couldn't tell you to this day! I think because I knew how ill I was before with no diagnosis, I was ready to start whatever it took, already quite mature & smart for my age I understood a lot more then people perhaps thought.
I've had to change my entire life plans & goals because of this, I was an A* candidate aiming to become a doctor myself who fell into completely failing my A Levels for reasons relating to my illness as I became very anxious around that many people, particularly teenagers as they can be terribly insensitive & not particularly good at accepting things from the outside. BUT this has not stopped me having a life, I worked in a very well known company's head office for a while & after this little stint of problems I aim to get back into college/uni and study nursing, it's not what I initially set out to do but it's a very very good compromise!
Upon leaving that kind of scenario I am fully confident and happy with who I am and that does include this illness.
I've never felt moping & feeling sorry for myself & asking 'why me?' was the right route for me, it feels like even now it'd be a downward spiral, mine was always almost a revenge tactic, a bit of a I WILL do this just to stick my fingers up to these difficulties & show that I am as good if not better than a perfectly healthy counterpart.
It is tough & everyone deals with it personally in their own way so I really do wish you the best.
You have Crohn's, Crohn's does not have you!!