I was preparing for three stages of physical attack and then they started. The first was manageable: light and easily bearable, hits and light kicks. There is a pause and then begins the second stage: much more intense but still manageable. Then the final stage which is brutal and violent, and I make every attempt to fight back but I am paralyzed; I want to move to defend myself but I cannot make my limbs move at all, and I am being violently beaten, feeling defeated as if they won. Whoever they are.
My goodness. This dream is relatively straight forward, I'd say. You're feeling assaulted. And though in the dream the attack is physical, in reality it could be emotional, psychological . . . Or, yes, physical. Or all of the above.
Remember, too, that emotional and psychological beatings take a physical toll.
What is unclear to me is where in the process you currently are. You say you were preparing for the attacks, so you seemed to know they were coming. This could be your subconscious sending up a warning flag so that you can ready yourself for future troubles. But maybe you have already passed through one or two, or even all the stages you mention. Maybe you successfully fended off some early problems, and then some more difficult issues, but are now feeling defeated and paralyzed, unable to get up and try again, incapable of taking any more.
It is interesting that you cannot see your assailant(s). This suggests that there is no one part of your life that is causing you particular trouble, but that you feel life in general is beating you down. Honestly, when I hear/read about this kind of dream, I feel a deep concern for the dreamer because I worry that the person might be depressed and in need of more help than I can give them with simple interpretation. If you truly are feeling defeated, my advice would be to find a counselor of some kind to guide you through these rough waters. And if you already have one, good! Keep up the fight as best you can.
Which brings me to my disclaimer: These interpretations are for entertainment purposes only and are not meant to act as medical advice of any kind.