Am I just doing everything wrong?


Just after some advice really.
We had an awful day with my son yesterday.
I had the sprinkler out and my daughter jumped on the hose and it sprayed high. My son got wet.
He wanted to use the sprinkler
So it seemed OK. He was laughing, then a flick of a switch
He absolutely lost it! By getting wet.
To an extent I have not seen before.
He absolutely trashed the garden, he broke the hose and launched every thing he could
The green bins and all the toys (little tykes cars)
He ripped the swing ball out that is so stuck in the hard mud, he just threw everything, including a filled water tray (so heavy)and then threw things at me that were hard.
I let him carry on until he threw things at me.
Then I carried him inside. This has put my back out.
I just honestly don't know if I handled this situation correctly.
Could I have done better?
He totally lost it.
No treasure box would work
I couldn't reason with him. He hid under the trampoline for 40 mins screaming.
I just need advice that what I do is correct? And if not what on earth can I do in these situations? Today I have felt exhausted and just a total awful mum, all day.
I don't know how to help this huge meltdowns and I just think I must be doing everything wrong.
Thank you so much for reading