Hi mibella: So sorry to hear you're dealing with this.
It seems when our sleep is messed up, our days are, too!
I have never checked into using a CPAP, but a few years ago, really struggled with sleep. I'm a light sleeper, too. Even when I'm tired during the day, I try hard not to nap. Instead, I do a little prayer time then some light reading for a few minutes. It generally picks me up a bit.
I resorted to some natural things like lemon balm or chamomile tea, valerian and melatonin occasionally, avoiding the computer for some time before bedtime, relaxing and reading, prayer, mellow music, and using lavender aromatherapy (also, I love the lilac scent, so I sometimes took a whiff of that, too). I didn't do/use all of these at the same time, of course!
Caffeine and sugar, I really have to watch. I've pretty much given up caffeine, and even a little sugar in the evening can keep me awake (as it did just two nights ago!). I'm seriously thinking of cutting out ALL sugar in my diet, except for natural, fruit sugars (and those in small amounts). I understand it's helpful for digestive issues to avoid sugars, and I have gastritis and IBS, so that's another good reason to cut them out.
Also, you might want to do a search on "foods that help you sleep." I think turkey is one; also banana and sunflower seeds.
Of course, check with your doctor before starting anything new. There's a chance there could be some bad interactions with any medications you might take, or you could have an allergy to the oils or teas.
Have you checked back with your doctor? It seems sometimes we have to hound them a bit to make progress.
Sorry I'm not more helpful. I hope things turn around for you soon and you get some good rest. Keep us posted and wish you the best!