Well, I didn’t have much trouble with my two kids, mostly because I headed 'em off at the pass before it really started. As soon as they’d start up with the tantrum behavior, I’d send them to their rooms and wouldn’t let them out until they were calm again–they were convinced that the rooms were absolutely soundproofed and I did my best to keep them thinking that way.
Then my sister moved in with us. With her two year old. Who was an accomplished tantrum thrower with separation anxiety. Whenever he threw a tantrum his parents would make a big fuss over him, alternately threatening punishment (that never materialized) or bribing him to stop.
He threw tantrums starting at about a half an hour after she left for work, and they’d continue for HOURS. Day after day after day. I’d put him in his room and keep putting him in there no matter how much screaming and throwing things he did. Sometimes I’d have to tie the door shut to keep him in or else he’d come out and scream and throw things all over the house. This went on for MONTHS. EVERY DAMNED DAY. Never once did I give in, never once did I acknowledge that I could hear him screaming. The only thing I could hear was a civil voice asking “may I please come out now?” If he could stay cool and not throw more tantrum he could stay out, otherwise it was back in the room again.
At one point my sister came home during one of these exhibitions and started to go let him out. I told her flatly that as soon as that door opened, she’d be out of a place to live in minutes. She whined and damned near threw a tantrum herself, but I didn’t give in to HER either!
Upshot was, eventually the kid learned never to throw a fit around me again. He’d throw them for his mom, but not me. To this day, he respects me even though he grew up to be a pathological liar, cheat and thief–he’ll lie to me, but I tell him that I think he’s full of crap and he KNOWS never to steal from me.
So yeah, never give in, never give up and stay sane no matter what. Don’t let the pattern get established and you’ll all be ever so much happier in the long run.
They DO get over it eventually–if only because they turn 18 and you can throw them out…