Hi Gingernut
The Epworth score is a screening tool for daytime sleepiness. This may be caused by obstructive sleep apnoea (OSA) but may be due to other causes.
The screening tool for OSA is the STOPBANG score.
Paully there is only one OSA which is where you stop breathing in your sleep. Some but not all sufferers are tired in the morning and nod off in the day. It can cause many problems and as you say carries a risk, but if treated these risks fall away.
The best way to get help is a referral to a sleep clinic (only a sleep study can give a definitive diagnosis) or failing that an ENT surgeon. Self prescribing CPAP may not be the best idea. It is also a significant risk in relation to a general anaesthetic so many anaesthetic preassessment clinics also have an interest in the condition.