I have had night terrors and sleep paralysis for years, decades even. Mine were not triggered by drugs or alcohol, but by stress. Stress about recent past events or upcoming events... The night terrors and paralysis lasted for days or even weeks (and it's exhausting!) until I was finally able to figure out and work through that particular stressor. For instance, one bout I had was right before I graduated from college...and had no idea where I wanted to go with my life after that. When my conscious mind worked through it, my subconscious mind finally let me rest, and sleep.