Stick around, we can help. Sometimes just talking about it can help.
A strong suggestion - get your hands on a copy of "The Explosive Child" by Ross Greene. It really helps. I am about to outline a little of how it works.
Your daughter is 15, which means some bad patterns have been set up which will need to be unlearned (by you and her). Sometimes a lot of what is wrong is that you are trying all the usual parenting techniques, all the discipline methods, which you were raised with and which have been so successful for others. The trouble is, these often not only don't work with difficult children, sometimes they can make our kids far worse.
I said on someone else's thread, I don't treat ODD as a specific, separate, incurable disorder which I just need to learn to live with; instead, I view it as a set of problems which have been caused by a clash between my child's brain functioning, and my discipline methods. I can't change my child's brain but I CAN change how I handle him. And it has made a huge difference to us.
First step - don't try to discipline if it's not working. It is better to not engage at all, than to engage and lose the battle.
Second, work out what is making her tick. Get inside her head. What upsets her? What does she like? What does she hate? How does she seem to think? And most important of all, what pushes her buttons and makes her really rage at you? And how can you prevent such a rage when you notice one beginning? What are the early warning signs?
Third, make a list of all the things you want to change about her; all the problem behaviours.
Now look closely at the list. Some of the things on the list are likely to be beyond her capabilities at the moment. Forget about her age - our kids mature in different ways, at different times and cannot be held up for comparison based on their age. difficult child 1 is very bright, but is still not good with self-care issues such as washing himself, changing his clothes and tying his shoes. He chooses shoes which don't have laces.
Now look at your list again. Choose the behaviours you feel absolutely MUST be dealt with NOW, even if it leads to a meltdown.
Chances are, this is a long list. But sorry, you must cull almost everything. The only things which should be in this first list - Basket A - are immediate safety, and maybe school attendance. For example, you have an impulsive five year old who hates to be touched, but his ball has just gone out onto the road and a truck is coming. You would grab the child to stop him running out in front of the truck, even though you know this will provoke a meltdown.
Now look at the stuff you have just culled from your list. Pick the five most urgent/important things and call them Basket B. These are what you will work on for now, but if you notice a rage beginning, you will back off.
Everything else goes into Basket C - we're not dealing with these at all for now. Only as things improve and graduate out of Basket B, do you move things from C to B.
What should begin to happen is at some level she will begin to see that you are trying to help her maintain control. This is appreciated. The child eventually comes to see you as an ally instead of an adversary. As this slowly happens, the automatic oppositional behaviour should lessen. Of course, it can come back in a flash at a later stage but sticking with this technique seems to increasingly lead to better self-control and subsequent progress with learning more appropriate behaviours.
You may find some things just don't seem to be improving. If this is the case, it could be that it's simply beyond her for the moment, so move them to Basket C and put something else in its place.
This method sometimes seems counter-intuitive, some observers may accuse you of giving in too easily or spoiling the child. It's not. What happens is that the child begins to feel more in control and less like a game piece being moved around on a chess board by someone else and more able (with experience) to make their own good decisions.
Punishments - forget it. Chances are, it's not working. What you need in place is good communication and natural consequences.
Example of natural consequences - if you're cooking dinner and you leave the pan on the stove to go read a book, the dinner will burn. Good food will have been wasted, dinner will be inedible and the family will be cross with you. This is the natural consequence of you walking away from the responsibility of cooking dinner.
Another natural consequence - your child takes money from your wallet. The natural consequence is that the child has to pay it back, and also has to expect to not be trusted again for some time. Trust will need to be earned back and the child will also have lost a lot of freedom and privileges which are associated with trust. Grounding a kid as well - not needed. Punishment apparently as justice often is interpreted as vengeance.
If your kid has driving privileges and crashes the car, this is an automatic grounding because until it's repaired, there is no car! You can add to this if you choose, a requirement for your child to pay for the repairs (some or all). There need be no further punishment, because the natural consequences are in themselves apt and effective. It also means the child can't blame you for their punishment. The only person they can blame is themselves.
And that's another thing - too often we, and hence our kids, are focussed on blame. This means that the child who feels everything in their life is wrong, will always try to assign blame for each little thing going wrong. It's important to get away from ANY blame as much as possible. Sometimes bad stuff happens to good people - it's true, but hard to accept. What we need to do instead of blame, is learn to pick up the pieces and keep going.
Our difficult children learn from our behaviour. They aren't as capable of learning what we teach, they need to observe and mimic. So if you punish by vengeance (in their eyes) then they will punish you and their friends (and teachers) in the same way. If your partner uses the silent treatment on you if he is not happy, then your difficult child child will learn to do the same.
Conversely, if you model the behaviour you want, then it is more likely you will eventually get it.
Anyway, read the book. It explains it all much better than I can. It really does make life easier. It's not a cure, but it can be a big help.
Marg