Good for you Luke.
Even though I was DXed after an LP/Mylogram, I'm one who doesn't
believe that an LP is necessary, unless the MRIs don't show MS or a
brain tumor may be a possibility.
Yes, after your LP, do lay flat, with no pillow for 24 hrs, if possible.
I found that, after, if a headache started, it would stop, almost
immediately, if I would, lay flat- no pillow, for 10 or 15 min.
Watch the caffeine, I can't take it, makes my heart go pitty pat.