" Put simply, I'd say: "I would like to get rid of that tick that is been biting me all day long." I would not say: "I must be free from that tick." And that's why I'd use "rid of" with a cold, as opposed to "free" (it doesn't matter https://grantsforinsulationwales.blogspot.com/2024/08/how-can-pensioners-be-benefited-from.html