Quick reply –
The train journeys seem to exacerbate. Other than the fact that they are jerky, check the seating! I found anything flat up against my back/head i.e. mattress, straight backed armchair or settee (or worse a forwards headrest) worsened symptoms, as it pushes the head into flexion. It might be worth buying a horse-shoe shaped ‘cushtie’ to support your neck and head whilst your travelling, to keep your head and spine well aligned, therefore allowing free-flow of cerebrospinal fluid between the two structures.
Diamox causes me strong pins and needles in hands feet but I persevere, as those brief moments are small price to pay for otherwise improved comfort from head discomfort, eye pain, loud tinnitus etc.
Diamox can stop working if your blood levels change (get potassium, calcium and bicarb levels checked every 2 months).
Hope some of this helps