I SO hear you on the "I've been like this my whole life so didn't realise it wasn't normal"!!! That's exactly how I felt when I discovered what a difference going without dairy made!

Allergy and intolerance are two different things. TBH, you won't have much luck with striaght HCPs getting the kids tested for for a cows milk protein intolerance. In fact they will likely scoff at you. I had to find a naturopath who was experienced in the area (he was recommended by a friend). I initially went just for DS, but he sent us both off for blood tests as he (and I) suspected I had an issue too.

As for looking for replacements, be VERY wary of soy. As I mentioned earlier, both DS and I are intolerant to soy protein as well, in fact I think it's DS's biggest trigger. Many people who can't handle cow's milk have similar issues with soy. There are other, safer, milk replacements out there.

Good luck with your first shop! You will find that it will take awhile, but you do get better, and faster at it with practice!

ETA I also referred an IRL friend who is a BBer to the same naturopath for similar issues, I will see if she's happy to post her experiences in this thread