It can take 3 months before you are sure whether you are responding to Humira or not. Some people do improve a lot within 2 wks to a month but the most recent clinical trial results suggest most people take longer than that.
It could be that you weaned from pred too fast as pmedic suggested. In which case you need to call your GI - actually if you are that much worse I would call the GI no matter what.
My son had an intense flu-like illness that lasted about 4-5 days following his second round of injections so I am wondering if you are having this type of reaction too. His included high fever (104), belly pain, nausea and vomiting, generalized aches/pain, bad headache. Doesn't sound like you have all those symptoms but I thought I'd mention that too.
If you are having joint pain or swelling that's new or much worse and other systemic symptoms like a rash, especially one that comes out when you go in the sun, you could be having a lupus-like reaction to Humira in which case you shouldn't take anymore.
Bottom line - call your GI.