I was diagnosed with it in around 2002, DVLA were very kind (NOT) and gave me 2 days notice that my driving licence had been revoked.
I had to buy my own machine and masks / other accessories and servicing. I found like the others that after a couple of nights I was like a new person. The machines now automatically adjust the amount air pressure needed to keep the air ways open.
I used to regularly fall asleep at work, to the annoyance of some who did not know about my condition.
There are several types of masks one can get, the biggest one covers the nose and mouth, probably the one the hospitals use the most. The next one is a mask that just covers the nose, though if you breath through your mouth this and the next mask won't work. The smallest and tge neatest is one that has pads that basically plug the noses nasel openings,
Have a look on the Resmed site and it will show the different masks and machines (can't post a link as working of a pad).
I am now on my second acpap machine, thankfully this one was provided by the NHS, which has now saved me a fair few pounds a year in running costs.
It did take me over a year to get my driving licence back, yet a friend was diagnosed with the condition never lost his driving licence.