I don't suffer nightmares to the extent that you do, but there are a few things that I have found helped over the years, if you want to try them.
Recalling the content of the nightmare in the daytime with your objective mind, and if you understand where those nightmares might come from, working on talking, writing or breathing through those events so that they are not hidden from your waking life.
Another method that has worked for me, is to change the nightmare to give you a positive resolution of what is happening. That doesn't have to be during the nightmare, it can be done when you wake from the nightmare - so for example, if something is chasing you, picture yourself getting angry with it or flying up into the air away from it, watching getting smaller below you - or if something is broken, picture yourself being able to mend it and put it back together with your mind - whatever feels right for you. It's not a quick method, but when I did this as a child, I eventually remembered that I could change what was happening during the dream.
I hope that things will change for you soon.