I have a similar experience. My sister is a nurse so I asked her if I have a heart problem or something. She said that it's sleep apnea and recommended me to have an everyday routine walking exercises. So I followed her advice and I noticed that my snoring has stopped and my sleeping hasn't been comfortable since. It's also good to incorporate some breathing exercises while walking. There are a lot of breathing techniques that you can practice on. But if the problem still persist it is always advisable to go to a professional.
It does sound like sleep apnea to me and I would suggest you make an appointment to see a sleep doctor to have a sleep study done.
I believe you will end up having to use a CPAP machine so you can finally get a good nights sleep. I hope you have the study done so you can get to feeling back to normal.
Since you've noticed a change in your breathing, even in the daytime, you should get your symptoms checked out with your doctor. You should not "forget to breathe".
Thank you very much everyone for the answers, it was very difficult to choose best answer so I just went with the longest one, it had some good ideas I can do myself too.
Have you been able to discuss this with your doctor yet? How are your symptoms doing now? I hope you've had some improvement or at least have started to try to hammer this out with your physician.