Sorry to hear that. Dairy intolerance is very unpleasant. I had it for about 20 years, and it's recently started to improve. I think it started because I took several courses of strong antibiotics over 20 years ago, which can damage the friendly bacteria in the gut.
I was only intolerant to cow's milk. I was able to eat goat's milk and cheese.
Probiotic foods can help improve gut bacteria, like fermented food and drinks, and pickles.