Hi there. We just went through this phase with my DS and it's getting a TON better.
His tantrums were not as bad as your DS, but there was still quite a rough patch.
Now that I'm on the other end of this phase, my advice is to do nothing different at all.
I know it's hard and you doubt yourself etc. and people are critical, but it really is just a phase ... your DS is incredibly frustrated by limitations right now (some of them physical, some of them situational, etc.) but he will start to catch on to parameters.
IMO at that age they are too young to have tantrums specifically to get something. I think it's just uncontrollable emotions. JMHO though.
You will learn what sets him off and will be able to avoid SOME situations that are just too stressful for the little guys right now.
HTH. Your DH's mother has no idea what she's talking about. All people believe their children didn't throw tantrums when they were this age, and all children do, and all MIL's think you spoil your kids. It's just a fact of life I guess.

Now that I'm on the other end of this phase, my advice is to do nothing different at all.

IMO at that age they are too young to have tantrums specifically to get something. I think it's just uncontrollable emotions. JMHO though.
You will learn what sets him off and will be able to avoid SOME situations that are just too stressful for the little guys right now.
HTH. Your DH's mother has no idea what she's talking about. All people believe their children didn't throw tantrums when they were this age, and all children do, and all MIL's think you spoil your kids. It's just a fact of life I guess.