When you do the D/D Compassionate/Lovingkindness meditation, it may also be helpful to do it not just for people with bad dreams, but also for people who's life is a bad dream, so that we can see the difference between the dream and reality. But It's important, when you wake up from your dream, not to go straight in to the people, having Compassionate/Lovingkindness for people in the dream, but to remember to have Compassion for yourself before you spread out to others. I imagine that's what you mean by "D/D" -- you start with yourself.
Also, if you tend to have a lot of bad dreams with anxiety, it may be helpful to look into your life to see whether you're feeding anxiety in your normal life, and to strengthen your sense of refuge in your life. Sometimes anxiety comes because we're too focused on the insecurity and impermanence of life, without looking at what we can depend upon. It may be necessary to build confidence and refuge in our normal life, so that we feel we do have the qualities to depend upon to deal with the insecurity and impermanence of life. We don't just work with the dreams, but also work in our life to build a sense of confidence in ourselves, so that we have more courage to deal with life as it is.
And that is what we do need in order to be able to deal with life as it is. We need courage, because, as the Buddha is recorded to have said, it "is the nature of living in the world... the 8 worldly conditions follow the course of the world, and the course of the world follows the 8 worldly conditions: gain and loss, fame and obscurity, praise and blame, pleasure and pain." So, this is the nature of living in the world -- being confronted with these opposites -- and it is in times of distress that our courage can be understood. In order to have courage, we need to believe in ourselves, in our inner strengths. We have to reflect on these inner strengths if we're going to believe in them and let go of our negative self-image.