I know that you posted this months ago, but I'm holding out hope that you are lurking.
Are there any reoccurring themes in your nightmares? It's very possible that you have unresolved trauma.
Let me rephrase since you can't remember the nightmares. The fear when you wake is always the same, right? Is it the fear of your own life or something else?
Be absolutely sure you are really ready to remember this, it will traumatize you. Nightmares are one of the scariest things a human brain can experience. If you aren't 100% sure you're ready, wait until you are to try.
I'm not saying you're not ready (at all), I'm just saying you should only remember this if you're 100% sure you're ready and 100% sure you want to.
I disagree. Nightmares are terrifying when you're in them, but when you look back at them knowing they are not real they can often seem pretty tame, or even ridiculous.
I find nightmares to be really thrilling experiences, actually.
Which is funny because I'm pretty cowardly when it comes to everything else.