Headaches After Missing Embrel Dose?

I'm having surgery on my knee next week so I had to go off the Embrel until a week after surgery. Today woke up with a headache that felt like I had a bad hangover that will just not go away. I've got it to back off taking the Norco since I can't take the NSAIDs right now. I'm just wondering if this could be caused by skipping the Embrel? I'm also starting to have a little pain in areas that didn't hurt before. Basically I feel like crap today and I'm wondering if this is just the way it's gonna be until I get back on my normal meds.