Snoring, can't stay awake, fall asleep in the cinema, constantly feels tired.
You might have sleep aptnia, go to a sleep clinic and get yourself tested, there are even some these days which comes to your house so that you can get tested in your own bed. I'm not sure if your GP must refer you or whether you can just go to one.
They will hook you up to machines and test blood oxygen levels threw the night as well as some other things. The second night they will let you sleep with a CPAP machine and do the same tests again.
Ultimately if you have bad sleep aptnia you will have to get a CPAP machine to sleep with every night. From what I heard they can be a shlep in the beginning to get used to and they have a couple of side effects but ultimately they are life changing if you suffer from sleep aptnia.
Basically as I understand if you have sleep aptnia you never really reach a deep sleep, hense without realizing you never really sleep/rest well, this is why you easily and constantly fall asleep on the couch at home, in the cinema etc.
A CPAP machine basically creates positive pressure in your system and keeps the airway open allowing you to breath so you don't stop breathing at night.
My dad has the same but doesn't want to listen, doesn't want to get tested. A uncle of mine has a CPAP machine for a around 6 months now, it has changed his life. Appart from the snoring which is gone, he is well rested after a nights sleep, doesn't fall asleep on the couch anymore when watching TV etc, he said that he never realized how tired he was every day and that he actually never rested well at night. A friend of mine also uses one, he has been using it for around 5 years now.
This can be very dangerous as essentially you starve your brain of oxygen during the night, it can also cause kidney damage and a lot of other damage in the long term.