The evil presence you thought you felt may have just been extreme fear, seeing as how that’s a scary situation.
Why the sudden change? Was it due to the evil presence?
I used to experience this frequently when I was younger and at a period of my life where I was under a great deal of stress and severely depressed. I was awake and aware of my surroundings, yet I could not move a muscle, and would experience a variety of auditory and tactile sensations. One time I felt the presence of evil and felt it choking me, other times I would hear my husband or my children when they weren’t home, or hear footsteps in the house, etc. This was very frightening. However, after I was treated for the depression and had undergone counseling, etc. for the stress and anxiety this stopped. I might also add that at the time I was not sleeping much at night and was very sleep-deprived. I haven’t had an episode of sleep paralysis in over 20 years, thank God.
I also have developed a theory, although unprovable, and I haven’t found anything to back it up. I think that some of the old stories and legends about the incubus and succubus (demons who have sexual intercourse with humans) may have originated with episodes of sleep paralysis. Some of the stories are very similar–it happens when the person is asleep, a demon enters the person’s bedchamber, the person feels the weight of the demon and sexual sensations, and is unable to resist. Not all of the stories are like this, but many follow this pattern, and it makes me wonder if these aren’t instances of sleep paralysis. If one has never experienced sleep paralysis, it might be very difficult to understand how very real these hallucinations seem. I just though I’d put my theory in as a sidenote.
I see no reason for this to cause a crisis of faith. Most true supernatural experiences happen when the person is awake, not asleep. In the lives of many of the Saints, when we read about supernatural experiences, they are at prayer. The approved Marian apparitions have occured when the seers were awake, living their ordinary lives. Padre Pio did battle with the devil while he was awake. Those who have received the Stigmata are usually awake when it happens, often at prayer, and Eucharistic miracles occur while people are awake. These are all instances of supernatural experiences that had nothing to do with the sleep paralysis state.
I think that once the stress of working so many hours is relieved, the OP may not experience this again.