I have been practicing meditation for about three months now and up until now they have felt quite good and relaxing. The last few meditations I have done have felt really strange and uncomfortable, just as I feel as though I am in a deep state my body goes numb, Mr heart starts racing and the only way I can describe it is as if I feel like I am being pulled outwards. At the same time I feel like I am asleep yet my mind is alert. I am really enjoying meditation but this experience...
It is a little difficult to answer your question without knowing what type of meditation techniques you are practicing. If you want to explain that a little more, perhaps we can offer more detailed suggestions.
Sometimes we can have new and unusual feelings or sensations while meditating, which might feel strange or uncomfortable, but only because they are unexpected or unique to our previous experiences.
For example, you mention a feeling of numbness in your body. One of the definitions of meditation that Yogananda gives is to be able to "turn off the five sense telephones of seeing, hearing, tasting, smelling, and feeling (touch)".
When our energy begins to withdraw from the surface of our bodies into the deep spine and/or upper chakras, there certainly can be a sense of numbness all over our bodies. Perhaps this is what is happening to you and it is a good sign — it just make take a little time and experience to get used to it.
The racing of your heart, however, is probably not such a good sign, because in meditation, we are trying to slow down the heart and breath a bit in order to quiet the restless mind. I’d guess it is simply a fear response to feelings you are not used to having (numbness, being pulled out of your body, or body asleep/mind alert for instance).
To work with that sort of fear a very important thing to do when this or any other unknown things happen to us in meditation is to pray for help and guidance to God and/or Guru(s).