OP, you most definitely are NOT being controlling.
At all.
The thing is after 6 months he should want to be with you a bit more and see his mates around you, or maybe the odd weekend he'd have a night out with them.
Going out with his mates 3 weeks in a row and getting into such a state that he's cancelling plans he's made with you is just telling you that you are not really that important too him.
Honestly, I would take it that he's still very young, and his mates, and going on the piss, is a priority.
Nothing wrong with that in my opinion.
I just wouldn't be interested in being the girlfriend of someone who preferred being on the piss, than being with me over the weekend.
It sounds as if you are a bit more mature and are looking for something else.
People mature at their own pace.
His mates are his priority.
Personally, I think that is what your 20's are for.
I enjoyed those years, out clubbing till all hours. But my friends enjoyed that too.
Don't invest in a relationship that just isn't giving you what you want and need.
It's not fun being the partner of someone who likes being on the lash the whole time.
Drunk people are very dull.
Accept that ye are different people in a different place in your lives and move on.
Wishing you well💐