When I was younger I remember many times when I would be partially asleep and paralyzed and I would scream for my mom but it would only come out as a silent breath. I always got panicked, because I did not know what was going on.

Later on I realized it was sleep paralysis, and I've come to live with it, and even use it as a tool. What you seem to have is some type of sleep paralysis, where sometimes you are completely paralyzed, or you have moved into the next stage where you are in a dream environment and can sometimes move. Instead of fearing this, work with it. If you are paralyzed, close your eyes and don't try to move at all, and it will feel slightly more normal, and you will drift into a dream most likely, or wake up fully. If you are at a stage where you are in your bed and can move, close your eyes and visualize yourself somewhere nice, like a beach, the mountains, whatever. It should almost certainly appear after a few seconds. Even if anything appears under closed eyes, it is good, because that means a more normal dream is on its way.

Like I said, you really can't do anything about it, so you must adapt to it, and avoid the frightening aspects of it. Just try those tips.