Help with my report?

So this is my report but i am a,little confused by it. It said i had 94% efficiency but i was exhausted. I also felt like i was awake all night? But then it says "severe"? Any help would be appreciated. DESCRIPTION OF STUDY:

The patient was studied at the Center for Sleep Medicine in Inwood, West Virginia on November 1, 2017, for 451 minutes. She had a sleep onset of 5.5 minutes and a sleep efficiency of 94%. Sleep architecture demonstrates 2.5 minutes in stage I, 100 minutes in stage II, 38 minutes in stage 3, and 41 minutes in REM sleep during the diagnostic portion. During the treatment portion, the patient had 9 minutes in stage I, 134.5 minutes in stage II, 12.5 in stage III, and 57 minutes in REM. The patient had episodes of sleep-disordered breathing. Hypopneas, apneas and RERA. The patient's apnea-hypopnea index was 9.6 and 26.3 during REM sleep. The snore index was 246.3. The patient had a total of 181.5 minutes asleep before the application of pressure. The minimum oxygen saturation was 84%. The patient met criteria for CPAP titration and this was initiated at 4 cm and titrated for respiratory events and snoring. At a pressure of 8 cm, the apnea-hypopnea index was reduced to 0.6. The REM apnea-hypopnea index was 0. The minimum oxygen saturation was 90%. The patient had a total of 109 minutes of sleep at this pressure including 39.5 minutes in REM sleep.

IMPRESSION:

1. Sleep-disordered breathing, obstructive sleep apnea, REM related, severe, with oxygen desaturation.

2. Snoring.

Simply put, you have relatively mild obstructive sleep apnoea that is worst on REM sleep (which is very common). When they put CPAP on you part way through the night you got much better. You got more REM sleep (also common) and you stopped snoring. Ignore the sleep efficiency statistic, it is not important. Your impression of being awake all night and exhausted at the end are not unusual. Don't worry about it.

Do you have any specific questions?