High Strung

[sally]

Do you know anyone who is high strung? Have you ever called anyone that? Has anyone ever called you that? Is it an insult? Do guys ever get called high strung?

And yes I am aware that I can fit into the category of high strung.

It's definitely not a complement, irrespective of whether or not it's a valid assessment. It's a backhanded way of saying you're irritating, that avoids looking at why the person feels that way. People who have difficulty dealing with frustration are more likely to be irritated, and will typically blame that irritation on whatever triggers it.

So in other words you annoy him.