"Well you need to learn to get used to it" about unexpected routine changes

Just stop getting upset when your plans change unexpectedly? Why didn't I think of that! That will really cut down on the time I hide away to cry over it...

It's stuff like this that makes me want to get an official diagnosis, because nobody seems to feel the same way as me. Nobody seems near as bothered when stuff comes up last minute, meanwhile I have my entire week planned out in my head and if any of the plans I make for myself get upended by someone else, I get distressed and I'm so tired of feeling like I have to hide it.

But then I wonder if being able to keep it together until I can be alone means that I'm not autistic after all. Either way, I still don't think I'll ever get used to last minute change of plans...

Can anyone relate?