vacanze romane: My daughter at 2 years and 7 months

Last months were such a big improvement in Gaia's behaviour that I simply couldn't believe it. I saw such a big progress and sudden calm (as always in her case, relevant). Though, there were fewer tantrums, she communicated much more easily and I was so happy to be in her company. I believed the bad moments had belonged to the past and we deserved not to go through any 'terrible two+'. How naive it was!
I noticed a new phase exactly two weeks ago. We went for a (pink) ice-cream and after a few minutes of mutual happiness, it all started. She threw a tantrum because she simply wanted another one. The same repeated in a shop later on when she just didn't want to give back a trolley. And since then I am terrified as it can happen every moment.
Why do I write about it now? Because our Easter holiday turned into a nightmare. Even if she calmed down on Sunday, I didn't. I was traumatised after Gaia's performance a day before. She had tantrums every ten minutes for most stupid reasons. The same minute she was happy, she swifted into screaming and kicking. Tantrum because of not wanting a shoe. Tantrum because of wanting a big glass. Tantrum because of not a proper jacket. Neverending reasons that even satisfied turned into another yelling for another reason. Vicious circle. Add our different approaches towards this behaviour and you will get a recipe for a perfect getaway.
I know she needs time to adjust to new places, I know she is sensitive. I also know it's NORMAL (???) for 2,5 years. But how to survive it? How to resist in public places, in restaurants, playgrounds? How to remain sane?!