3 1/2 mood changes

Hi. My 3 1/2 year old daughter is generally very well behaved, but lately her mood changes have gotten way out of hand. She of course has the normal behavior of testing me, saying no to requests and all that. But in the last month when we tell her to do something she doesn't want to do, like go to bed or that its time to leave the park, her anger has exploded. She will scream bloody murder, hit, kick, throw anything she can, bite, hide and not listen to any authority (like a lifeguard telling her not to run.). When it comes to going to bed I have gotten to the point of walking out of her room and holding her door shut because I need a break and i want her to stay in her room, but she kicks and claws at her door screaming. I can't get my husbands help because she wont let him do anything with her. Everything is "not you, i want mommy!!" Which I understand because I stay home with her and my son. But at random times, especially when she is angry she will say "I dont love daddy". Even when he isn't home. That concerns me alot. Like I have said, she is normally well behaved. She seems mature for her age alot of times compared to others in her playgroup. But when she loses her temper shes like a wild animal. Sometimes her fits will be over something as simple as saying Im sorry or thank you to a friend. I will remind her to say one of those and we will have a 30 min crying, screaming, throwing, complete meltdown.  And it doesn't matter who is around, like a group of her friends or in public. Im at my wits end with her. Her sleep has been going downhill also. When I try to get a nap out of her she will rip all the bedding off her bed. Been waking up at night crying, sneaking into bed with my husband and I, which we have never allowed.  I have an almost 1 1/2 year old son who trys mocking her behavior sometimes when shes acting this way. I do everything I can to be consistent with her, when she acts up she gets things taken away, when she gets up at dinner, shes done eating. All those except time outs. I dont know how to make that work with her because she will not stay in them, so i have started sending her to her room because we do not have toys in the kids rooms, only books are allowed in bedrooms. Is this normal for her to be so angry all of a sudden? People tell me its a phase, but its becoming more and more often. Please help!! I dont want to be fighting with her all the time and I want to be in a good mood again.

[margypops]

Then dont fight .,perhaps she has learned it ,perhaps she is feeling jealous of attention the younger sibling is getting .focus on her positive side and praise her when you see her doing something right ...

[kformas]

Trust me, I only fight her when I have to, but I do have to stand my ground on things (like when its time to leave the park, we need to leave. Or when its bed time its bed time)  and lately she doesnt ever cooperate.  I do praise her when she does something right, and thats what my problem is, she isnt doing right things anymore. Could be jealousy, didnt think of that since there wasnt any when he was born.

[margypops]

Most children get jealous when a new sibling arrives, they dont get the attention they used to get and they see Baby getting lots..So thats when you up the attention make sure she gets some one to one time with you and her Dad , leave Baby with Dad and you take her out,  let Dad take her out,one to one . focus on making her feel special,In the park tell her 10 mins before you have to leave , then remind her 5 mins later. .No child likes being shut into a room and the door held you are only firing up the issue . There is a good book out there SOS help for parents by Lynn Clarke it has helped many ...to interact better with their children ..Good luck it isnt easy ...