How long is a piece of string? Hopefully you'll get a meds regime that will bring flare ups under control. I'm afraid it's a bit of an unpredictable disease but the best thing you can do is listen to your body and get to know the signs and symptoms. And if your body tells you to rest, rest or you'll pay for it. I've had Crohn's for about twenty years and probably for sometime before that - it can take ages to be diagnosed. My symptoms were put down to stress til a smart GP sent me to a specialist.
In my experience stress is a factor. It doesn't cause the disease and I don't think it makes the underlying disease worse but it can precipitate a flare up and make things seem worse, in my opinion.
I recognise the feeling of being relieved when you got a definite diagnosis. Plus it means you can actually research it. As others have said there's good info on the web.
This UK site is good -
http://www.nacc.org.uk/content/home.asp
You may have to be persistent with your docs until you get a treatment regime that suits you, but keep going. Mine is reasonably well controlled by drugs with only occasional flare ups. Because of fatigue issues you are best to try and eat a normal diet unless you can identify foods that are causing problems - for me onions, fatty foods and cream are the main culprits. But I still eat them from time to time - I just plan ahead!
Good luck and take care.