when do u say its too much

You can't really control how the person is going to feel. You can only be as diplomatic as you are able to, or want to be. Restraint is a choice, barring mental dysfunction. Some people just choose not to exercise it.

AS far as being able to get something through to someone. Sometimes you just can't. Everyone thinks differently. Do you know, there are people who have brains that are not equipped to process sarcasm? They are regular everyday people, but they cannot grasp that concept.

And too, the people in your life need to come to understand that maybe, you aren't very good at putting things delicately enough for them. Perhaps they could offer suggestions on things you might say to make it more palatable for them, whether you choose to do so is up to you.