Hi,
Why blame your dreams? No matter how bad a dream seems, your subconscious creates it to help you in some way. Sometimes you have to be woken from sleep, other times you have to be entertained to stay asleep. When morbid thoughts intrude into sleep your subconscious creates a strong dream to divert you from them or wake you up.
If you are used to sleep medicine, when you leave off you suffer withdrawal simptoms. That needs a strong dream. If you take sleep medicine, you often need a strong dream to wake you up.
Your own subconscious is omni-present and omni-scient, trust it to do the best for you!