I am seeing a common theme here and it is extremism.
If dairy is the trigger then by all means cut it out.
What i am seeing here is " I cut dairy out for a long time then all of a sudden at a load of it"
Two things here. Overly restricting on said food product can actually cause the food sensitivity. I can't remember the name of the study but it there is good info on this.
Binging on the said food. So you a cut a food out for a year then all of a sudden ate your body weight in it all in on day. Of course this going to have some kind negative effect. If you ate too many veggis in one sitting it will have a bad effect.
Try and keep it logical cutting foods out. Firstly try cutting down on the food for a few months and see if things improve, If there is zero improvement then logic would suggest this isn't the trigger. If you so wish to cut it out altogether then go for it but at least you cut down slowly.
Extremism is not the answer.
I hope you're not referring to my post, because I have always consumed beef and dairy with some consistency, like a hamburger every other week, cereal a few times a week, quite a bit of cheese, but not so much that cutting back wouldn't mean cutting it out completely. And never so much acne that there wouldn't logically be a correlation. Who has dairy every day? Lots of assumptions ^
For me, extremism absolutely was the answer. When you're inflamed, no one has time to cut back this, wait a month, then try that, rinse repeat. imho. I got relief fast.
If i was referring your post then i would have quoted it.
Answer me this,
Is extremism sustainable? For me it is not sustainable. If something is not sustainable then how can this be a good habit to adopt?