You don't take Ivermecting every day. You take it for a certain number of days on and off, depending. I took mine 2 days on, 2days off, but I believe it's usually 4 days on, 3 days off. If you go by what ICU writes in her protocols, it's safe to take it for up to 6 weeks at the above rates.
Since Iver is taken by weight, you only take it once a day. What were the doses they told you to take 3 times a day? Or did you mean 3 times a week?