From personal experience, it's easy to lose Concentration or wake up suddenly in Lucid Dreaming because it requires advanced Mental skills, so it can be difficult to learn how to do it. It is also influenced by the fact that you do not have an understanding of the systematic nature of Self Awareness in dreams, so in the beginning it requires consistency to become Aware of yourself in dreams regularly, otherwise if you stop practicing, you will also stop being Aware of yourself. For a very Strong and Wide Consciousness there is no problem with this, so there is an intertwining with Meditative skills.
However, it is worth noting that Lucid Dreaming is a Physical skill and is accessible to people who are far from Spirituality, whereas Astral Projection is quite different, although to be fair, from Lucid Dreaming you can easily Project into the Astral if you understand how to do it, but the Soul must be Malleable enough to do this, as well as its Connection between your Body and Consciousness.
The difficulty is that Lucid Dreams are, roughly speaking, a different «space» where somewhat different laws are in effect, unaccustomed to the Physical Reality in which you are used to being Bodily Realized. Your Consciousness literally encounters dissonance when it gets there, and you can't hold your Focus for long.
As for your problem, I would suggest that you are experiencing, for the reasons above, an «aberration» of signals, i. e., an uneven overlap of the Physical, Mental, and Ethereal Bodies signals, which responds in you with similar sensations, such as feeling your limbs «out of place», or noticing the sheets and any surroundings, or feeling that your eyes suddenly can't see. At the level of the Spirit, this is similar to the process of the Consciousness trying to master Aspects of another Dimension, but still so closely connected to the Physical Body that «interference» occurs.
I also believe that your desire to hold onto sleep, «shout» commands, or «spin like a cub» can lead to Psycho-Emotional tension and excitement. Wakeful Consciousness begins to intervene too actively, and anxiety or anticipation of a successful outcome can cause wakefulness. It may be worth paying special attention to the Void Meditation to harmonize the Mind and filter it from information garbage before the Practice, so that nothing disturbs you. And in general, I consider it an important element of Lucid Dreaming training. You need a quiet, peaceful place.
You also mentioned leg paralysis or a twisted body, as I understand it. This can speak of Subconscious Blocks (even Energy Blocks in some cases), Subconscious fears or Psychological traumas. I won't say, as your case is not known to me, but based on my research, it is indeed true, such Psycho-Physical reaction is not rare, so obviously you need to work on it and Harmonize the state of Mind.
You also mentioned «blindness» when practicing the Method. The feeling of not opening your eyes or not being able to see is due to the fact that our «eyes» within sleep are not Physical organs of vision, but rather a transmission point for images from the Subconscious (and beyond). When you «Consciously» try to open them, you are making an effort based on your experience of the physical world and the system «fails». Do not try to interpolate into Lucid Dreaming the laws of the external world that you are accustomed to, because it will interfere with you. You don't need to focus on anything in particular, because most likely, when you first become Conscious in a dream, you will see something extraordinary for you.
My advices to you would be:
Practice Void Meditation more often. This is not a platitude, if that's what you're thinking, but quite sound advice. An Advanced version of this Meditation can have a significant impact (check out the website).
Keep a journal of any dreams during the Practice period. This Strengthens the connection with your dreams. The more attention you pay to your dreams in reality, the more natural and stable are their images and your Willpower influence on them.
Working with the Physical Body. Hatha Yoga makes your Union between Body, Soul and Mind Stronger, even any regular stretching is good to keep the Body free from clamps and tension. Pranayama also helps in establishing this Balance, as the meaning here is deeper than just the Yin and Yang Aspects.
Also read this postFull site ↗ of mine in the thread. In this post I have provided some additional information, tips, Practices and Sermons that will help you in mastering Lucid Dreaming and Astral Projection.
