Yes, I used to go through these phases myself, leading to months of intense panic attacks. I am able to stop this cycling 90% of the time now.
First thing I would say, it is ok to have these feelings. They are part of you and how you process the situation. Once the initial intense emotional period has passed then I try to work out the root cause of that particular feeling, often it is not the thing that triggered it but some underlying issue and there is the possibility I am replaying a script from events earlier in my life (I have a bad habit of doing that).
The next step is putting the current situation in its correct context. If there is a previous event or situation that is causing you to react to the current one to a degree that is out of proportion to what would be normal, then it helps to acknowledge this situation is different and why it is different, the two do not have to have the same outcome, you are in control. Whether or not that is the case, you need to acknowlegde how much control over the current issue/s you have. If they are outside of your control then working on letting it go to some extent can help. Focus on the aspects that are under your control. How can you improve the situation?
If the problem is cycling of negative/emotion ridden thoughts with no relief and it does not have a current trigger that you can address, then work at stopping those thoughts and distracting yourself. The thing that is bothering you can wait a few hours until you are calmer and can address it. Do something you enjoy and that will distract your mind until you find some balance and calm, and then go back and try to address it as rationally as possible.
This type of thing helped me and I hope it can be some help to you. I don't have any training, this is simply the method I have used and continue to use to help myself.