It does sound like your family on the other side was trying to contact you through this dream. Just from personal experience, I have found that dreams like this do have some significance to what is going on in your life at the moment. I apologize if I sound like an armchair shrink, but several things in your post really came out at me.
The phone number could have just been symbolic -- perhaps your family feels you are "losing touch" with something important? Thus, in your dream, you lost this important number for someone/something that could help you. That would go hand in hand with some of the stress issues in your life right now.
Just speaking from my own experience, during periods when I'm really stressed out, I always feel "numb", like "Heck, just pile some more on me. It isn't going to make any difference..." In essence, that numbness you felt may not have been a warning about a physical problem, but a warning of you've had too much going on in your life and you've become numb from the pressure and stress of it all.
I've had similar dreams about my parents and people who have passed on. Usually, there is a message in all of it, although sometimes it is a little jumbled and doesn't always make sense at first. I know several of us have made this suggestion to people regarding dreams; but, keep a journal of your dreams! This really does help and may provide you with some pieces to the puzzles that don't make sense.
From what you said, I believe this was your family's way of letting you know they are aware of what is going on in your life and are concerned and want to make sure you don't "loose touch" with what is really important. Pay attention to these dreams, I truly believe this is the way our loved ones communicate with us after they pass on.