Welcomed newborn and now toddler is a nightmare

In need of some advice. My toddler has always been a dream she has just turned 2. Yes she may have a temper but always been a great sleeper and generally well behaved. 5 days ago we welcomed our son to the family and since then she is refusing to sleep she is throwing tantrums she is trashing her room and I generally do not know how to handle her. I know it’s a huge change for her which she needs to adjust to I guess I just underestimated what impact it would have on her. Anyone else been through the same thing? How did you handle the situation?