Disclaimer: I am in no way an expert on the issue. Our 4 year old never had these kind of explosive tantrums but our now 2 year old is making up for both of them! These tantrums can last up to an hour and can be because we took something away or because his feelings got hurt. I asked Instagram what their advice was and got lots of helpful feedback. Here is what I've discovered works for our 2 year old and hopefully it will help for you too.
That's it. When I try to talk to my tantruming 2 year old it makes it worse. I have found holding on to him (usually on my lap not facing me) and I breathe in through my nose and out through my mouth deeply after about 30 seconds to a minute he is mimicking my breathing and is able to catch his breath.
Now, there are also times when he is trying to get his way about something and in those times I usually will finish what I am doing and ignore as a lot of people suggested. But ultimately I don't want to leave him alone to cry it out (it doesn't work for him, I've tried), I want to teach him how he can help himself when he feels out of control like this.
Not only does it help him calm down but it helps me too! Because hearing your kids scream and have a fit really is stressful!
Hope this will help someone else out there going through the same thing!