I was diagnosed with moderate sleep apnea two years ago, and got a CPAP machine. Similar to you, I am not overweight, and my father had severe snoring issues. It really made a big difference in my sleep quality. I was waking up feeling tired all the time, like I barely slept, and after getting used to sleeping with the machine, I started waking up feeling refreshed. Instead of falling asleep all the time, I suddenly had energy to get through the day. Almost a night and day difference. For you, having a more severe case, the difference might be even more dramatic.
The CPAP machine I have comes with a humidifier built into it. There is a removable plastic reservoir, that according the manual can only be filled with distilled water. The only thing that scares me is the cost of a new one if this one breaks down, which I'm sure it eventually will. Insurance covered most of the cost of this one. I don't know if I will be as lucky next time, and they are not cheap.