Yes, it is a complaint. The definition of a complaint is pretty much grumbling about anything we're not too fond of.
Anyway, the fact that she says you're complaining *too much*, which means that it isn't just about this one text. She sees you complaining often and wants you to either accept your choice without complaint or change the issues which are making you complain.
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I just wanted to add: Grumbling about your work choices.... threatening violence on someone who looks at your girl funny....and getting upset because she warns you off....
Dude, you need to freshen up your outlook on life.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.