I fixed my sleep apnea using a Velumount device, which is simply a piece of wire you stick in your throat before you go to sleep, and it keeps the important part of throat unblocked during the night. One of those things that truly deserve to be called "life hacks".
Learning how to use it is a lot of "fun" (expect to spend half of the day vomiting until you learn how to insert it properly), but afterwards it works like magic.
I would recommend to try it, and verify by oxymeter how it works.
According to velumount.ch (and the other location sites), it does need a fitting session to mould it. I wasn't able to find a price list for my country and the doctor who would do the fitting is in another city, so it is pricey overall it seems. Especially if the Swiss pricing is anything to go by.
The product itself seems like it's supposed to be malleable to adjust to the individual, which kind of makes the fitting session + workshop seem like rent seeking. Just give me an instruction booklet with FAQ and warnings.
Not sure if I understood it correctly, but the branch in Hungary seems to do it for 120000 HFT = 350 EUR.
If you have a friend who is a customer, he could (this is cheating) buy one for you (pretending it is a replacement for him), and explain to you how to use it. You save a lot of money, but the disadvantage is that it is not fitted for you. I am not sure what difference it makes.
So, if that is an option, I would recommend buying one via friend, testing it (with oxymeter), and if you are satisfied, follow the official channels (through Hungary). At the moment you are sure the solution works for you, I think it is worth the money, considering how costly and/or inconvenient are the alternative solutions. (Then you can do an extra test whether having the wire fitted for you is an improvement.)
(It would probably also make sense to take photos of the wire immediately after you buy, so that you can try making duplicates later when the original piece breaks or loses shape.)
Their web page says Switzerland, Germany, Netherlands, Austria, Hungary, South Africa, India. Note that the prices may differ.
Yes, the wires are custom shaped. (But they work even if you use a version shaped for someone else with similar head size. I don't know how much difference it makes compared to shaping specifically for you.)
Learning how to use it is a lot of "fun" (expect to spend half of the day vomiting until you learn how to insert it properly), but afterwards it works like magic.
I would recommend to try it, and verify by oxymeter how it works.