I actually look forward to sleep paralysis events. If you can get past the panic, and the ensuing sense of presences, then you can jump straight into lucid dreaming. It's like a lucid dreaming free pass.
I theorize the malevolent "presences" that you experience are simply a very deep and limbic response to the terror of waking and finding yourself paralyzed and trapped in a familiar yet haunting dream landscape. The presences are not at all unlike the feelings of dread and inexplicable and troubling emotions you feel after a traumatic event -- as if the traumatic event has an almost "demonic" quality or face to it (that's how the base mammalian brain logs very serious and dangerous predators and chains of events in memory, by assigning malevolent agency to them).
If you just tell yourself when you wake up in the dream not to panic, don't scream out, just relax into it, then you will circumvent the whole incubus phase. Then you can ask yourself, where do I want to go? Should I try swimming through the air and out the window, should I explore this place a little. Or you can just close your eyes and relax and fall back into the prickly blackness of sleep.