If your doctor has given up on you (it happens), you need another doctor, especially if this doctor isn't actually a dermatologist specialist. Get referred.
In the meantime, you need to start keeping a diary. Things to track:
- What you've eaten (especially if you've tried something new)
- What chemicals you've come into contact with (e.g. did you wash your hair, wash the dishes, do the laundry?)
- How you are feeling (stress can be a trigger)
- How your Crohn's is (other health problems can be a trigger)
- Where in your monthly cycle you are, if you have periods
- What medication you took and how often
It's a lot of irritating logging, but unless you track it all, it's hard to pinpoint what, if anything, is making your eczema flare up. Your new doctor will also find it helpful.
Allergy testing is a must if you haven't had it already (and as a result of the above log, you might identify some non-standard allergens to get tested for).
If your eczema is cracked and weeping all the time, chances are you are regularly getting it infected - make sure you are getting appropriate steroids for when that happens, and not just relying on your standard stuff.
You'll see conflicting advice on how often to shower/bathe - TBH, as long as you have a product that doesn't irritate your eczema (if you're really miserable, you can get stuff prescribed), there's no right answer. Do whatever you find helps make your eczema feel more bearable.
As well as using the right medication, I've found when in that state of being utterly miserable, cold compresses help relieve the pain/itching - just flannels (washed using a non-bio detergent) that you keep regularly topped up with cold water. It depends on the site of the eczema too, what you can reasonably do to keep comfortable.