Wow. You must have been dealing with the best of the best.
DPS, if you were going get tapped, it would have happened already. For future reference to anyone else that gets a headache following a lumbar puncture, this should last a day or two, at most, and is quite common. Any longer than that, you should be requesting a blood patch. The headache is caused by your CSF continuing to leak from the hole they punched in your spine because you dont have clotting factors in your CSF, so they have to go in and patch the hole with, well, blood. Three weeks is quite scary, its amazing you didnt pick up a secondary infection.