For some reason I think of samotna more as lonely rather than alone. Would it be appropriate to use sama instead of samotna?
I agree completely, I will change the default to "lonely". Yeah, "Nie jesteś sama" would be "You are not alone".
How can you tell someone they are not lonely. Except if you are a doctor telling them they are misinterpretating a different emotional state. Telling them they are not alone. As in you are there with them would be possible statement