Stop being afraid and just let go; you are safe no matter what you’re doing.
I understand this blockage—it mostly stems from fear, fear of trying something new, something that may have never been done before. This is a strange experience at first, especially with astral projection. I believe you’re doing everything right, but when it comes to taking "the final leap," that’s where you get stuck.
Advice: Try to be more at ease. Learn to relax deeply. Practice breathing exercises to calm yourself before bed or when you're preparing for astral projection.
Make peace with the idea that everything is okay and will continue to be okay once you do this. You probably need to relax not only your body but your mind as well. This is a matter of perception and fear, which has nothing to do with your progress. Let go of the fear, and you’ll be fine. Trust yourself more.