Deborah,
Hello and welcome! I, too - have problems with REM sleep!
I hope this information pasted below is of some assistance to you.
THIS LINK should give you a better understanding of the condition.
Rapid eye movement
(REM) sleep is the stage of sleep characterized by rapid movements of the eyes. During this stage, the activity of the brain's neurons is quite similar to that during waking hours; for this reason, the phenomenon is often called paradoxical sleep. Most of the vividly recalled dreams occur during REM sleep. It is the lightest form of sleep, and people awakened during REM usually feel alert and refreshed. REM sleep is so physiologically different from the other phases of sleep that the others are collectively referred to as non-REM sleep.
Physiology of REM sleep
Physiologically, certain neurons in the brain stem, known as REM sleep-on cells (located in the pontine tegmentum), are particularly active during REM sleep, and are probably responsible for its occurrence. The release of certain neurotransmitters, the monoamines (norepinephrine, serotonin and histamine), is completely shut down during REM. This causes REM atonia, a state in which the motor neurons are not stimulated and thus the body's muscles don't move (AKA paralysis). The lack of REM atonia causes REM Behavior Disorder; sufferers act out the movements occurring in their dreams.
Heart rate and breathing rate are irregular during REM sleep, again similar to the waking hours. Body temperature is not well regulated during REM, and it approaches that of the surroundings.
The eye movements associated with REM are generated by the pontine nucleus with projections to the superior colliculus and are associated with PGO (pons, geniculate, occipital) waves.
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In smaller terms, I personally am just tired a lot. The problem with being sleep deprived (for me, as I have a seizure disorder) is that this can trigger my seizures, which makes me even twice as tired.
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Here is another link you can check out:
The Effects of Sleep Deprivation on Brain and Behavior
I hope this little bit helps you out.
-Ellie