I am dealing with that right now, and it is probably the worst symptom of all, because it is both pain, fatigue, and mental unclarity all rolled into one.
I have two types of bad headaches. One is like a bad bad tension-type headache. That is usually mitigated or alleviated by Fioricet, narcotics, nsaids, etc. I have these very, very frequently, multiple times per day
The other type I get are frankly almost indescribable. They come on suddenly, like a ton of bricks. The first time I got this type of headache I literally turned around thinking someone hit me as hard as they could in the back of the head with a hammer! I have light sensitivity, lightheadedness--as in, if I stand up, I feel like I will pass out for about 2 minutes before I get my bearings back. I never have actually passed out, although I usually feel like I am going to. If I turn my head to the side, or look straight down with my chin tucked to my chest, I will get weird pins/needly sensations which can trigger onset or make worse. Absolutely NOTHING helps these. Not fioricet, not nsaids, not narcotics, not any of the off-label meds they said might help... Fortunately I don't get these as often as the other type, but still get them WAY too frequently, like 5x week or so.
Are you taking prednisone? I could seem to link the really bad headaches to prednisone. When I increased or decreased my pred I would be much more likely to have these, or if the prednisone dose was starting to wear off and I didn't take another dose exactly on time, it would almost always trigger. Of course, there are many other times i get them where there is no obvious prednisone trigger, but boy, I knew if I screwed around with the pred I would for sure get them.
I have tried fioricet (can be VERY helpful for tension type), perocet (can be very helpful for tension type, marginally helpful for bad type), iv morphine in hospital (not helpful for either type), dilatizem which is helpful for raynauds symptoms and heartrate issues and is supposed to be helpful for headaches and the verdict is still out on it. They are considering maybe trying amitriptaline, which is normally used for antidepressant. I was actually prescribed that a long time ago for off-label use for interstitial cystistis pain, and it made me feel sleepy and hungover all the time.
The other thing, that seems weird but is worth noting, is that I am prescribed adderall, and sometimes like on the weekend or day off work I will not take it in the morning. HUGE mistake. I will not be able to get out of bed all day if I don't take it and will have a headache for sure. But on the other hand, if I am working hard on a project or something and I take more than I usually take (but still within my allowed prescription dose) it can trigger a headache