I'd say drinking 'who knows what is in it' water is probably the problem. Cadmium, found in old water pipes with metal leech toxic as heck cadmium into the water--I was in the hospital for a month and came home with the same problem. But I'm sure you are not parasite free by any means---they just make you sick--not do the hula in your legs.
Cadmium makes your blood vessels spasm (which is really what that 'crawling' sensation is), which the 'elites' don't want you to know (even better symptoms for prescribing drugs--always their goal) but of course none of that will help including anti- parasite stuff, so You waste a lot of money and time buying pharmaceutical cartel products, both natural and drugs--they own both.
And depending on the water source, there may be other nasty stuff. :(
Try detoxing instead. Head them off at the pass, and save yourself a boat load of money.