There is nothing we can do about others assumptions really. People will always assume your intentions from your actions. The rub is that they assume their intentions with your actions. Its like saying you always understand what you intend with the speakers words. You think you agree when you do and you nod but actually you agree to your meaning and its not necessarily the speakers intent.
While reading your posts I remembered. Since I was very small I always tried to fix things or improve things. Because I was unskilled I normally broke them further and usually it was not my things. I grew up with a label of being the terrorist or the naughtiest boy in town when all I wanted was a little recognition. Someone to beam with joy and say "thank you"
When people assume they always reveal who they are more than what they think they are assessing. You say something and someone says its beautiful. That would be the beautiful person inside. The ugly person will see ugliness in your words.
So in the end when you know your intent, you can tell it once and if the people don't want to believe you then don't bother. Let them reveal who they are while you have peace knowing the real reason why you did what you did or said what you said.