Tired of dealing with this

But as much as I am at my ends with this guy, it's a situation I am learning from.

I don't know how to label him, maybe an insecure liar?
This is a situation is something right outside of my control.

I avoid trying to think of ways of helping/fixing him, because I have no power nor right to do so.
So I try to think of ways of being a good role model, and show him that it's okay not to be always right.

But to no avail.

I try to be lenient.
You can be bossy.
Noisy.
Degrading.

I'll tell you that I don't like the things he does, but I won't tell you what to do.
And all you say back is "That's just the way I am".

Then you try telling me what to do, like you always know better.
Then talk behind my back, making stuff up.

I get tired when I am being harassed through those text messages.

- - - - -

But I can think and think, and think of what I could have done better.
What do I do now?

But there's really nothing I can do, and I can only give it up to God.

This is definitely a situation that I cannot do anything, because I've really REALLY tried.
And I wonder if these situations happen often, and that I just don't realize it?