I want to complain about not having sex with my girlfriend
Why aren't you having sex?
I'm actually tired of the boring sex we're having
You shouldn't demand sex from your girlfriend, or demand a certain level of excitement.  This is a decision that should be made mutually, based on what you are both interested in and comfortable with.
We have sex almost every single day and I'm bored.
Well, the problem isn't a lack of sex, it's just the quality. I think it's best you seek some time of therapy for the two of you.