Coffee for a long time just made me feel better, improved the headache and just generally a little less ill. The past few months however its switched over and coffee is bad and I have had to avoid it
I've recently had this experience, too. It coincided with a sudden taste of ashes in my usual coffees--like someone had dropped cigarette ashes into the grounds and stirred everything together. Switching to a coffee brand that does not have much/any ash or roast flavoring stopped the headaches. I can also have caffeinated tea with no issue... well, as long as I remember to keep drinking water to counteract the dehydration.
Anyway, I often react to pollution with headaches, so I think coffee headaches might actually be polluted-coffee headaches. You said you have to avoid coffee but also that you find Sudafed helpful, and I'm pretty sure Sudafed contains caffeine. This makes it seem possible that something in the coffee, rather than the caffeine, could be affecting you.