Personally I have made over 100s orders of different things through the web and only rarely has a package been opened and never has it been confiscated by Swedish customs.
Good decision to join us at the drugs forum. Are you sure you have protozoa though? Have you seen doctors and asked for stool testing, sometimes multiple tests have to be taken.
Never despair, this is only the beginning of your health journey. If you need help always write on the forum and we will try to advice you.