Have you been checked for fibromyalgia, Rianne? It's not uncommon for people with illnesses like Crohn's to develop secondary illnesses like fibro, and this diagnosis would explain your fatigue and pain.
As far as management goes, you might like to look into getting regular massages, if you can afford it. Find someone who is experienced in pain and fatigue and auto-immune-type-illesses; start slowly and gently; and increase intensity and time as you're ready.
Tai Chi is also said to be helpful, and proper relaxation / meditation.
Another thing that might help is for you to become aware of your energy envelope, and to use pacing. This is a common rehab strategy with fibro / cfs and some other illness-related fatigues, and might help you tremendously, if you give it time. You can read more about
it here:
http://www.cfidsselfhelp.org/library/topic/Energy%2BEnvelope%2Band%2BPacingWarm water therapy can also help the aches and pains too.
All the best,
Ivy.