4 yo tantrums

[SecondhandTable]

My DC has been tantrumming since she was about 12 months old. She's always been 'spirited', 'high needs' whatever you want to call it and always had horrific long explosive tantrums. I feel they did decrease in frequency gradually between 2.5 and 3.5 although they were still pretty frequent. We had DC2 when she was a little over 3, she's about to turn 4 now. Over about the last 3 months or so her tantrumming is getting worse and worse. She will easily scream for hours at a time, every single morning she gets up and starts tantrumming within about 2 minutes of me or DH going to her. Every single bedtime at some point in getting ready she starts tantrumming. And many times in between. This is usually at home, she never used to tantrum anywhere else although now she occasionally will tantrum elsewhere too and this is also getting worse. She is apparently fine at nursery and has never tantrummed there. Me and DH are really struggling to cope with it now and the baby's sleep is badly affected by it too.

If anyone has any advice please about how to deal with her it would be much appreciated. I love her and she can be a loving, fun little girl but she morphs into this absolute terror so many times a day (and often even at night) and it's so draining.