Just you think you figured it out, I come along and throw a monkey wrench in your gears. Lol!
I was slightly overweight, non-smoker but did drink about three units of alcohol per day. I also could've exercise more. Found out I had fatty liver and decided to do something about it. I quit drinking altogether, and began eating healthier. I ended up losing almost twenty lbs in 6 weeks, but then started getting this constant need to yawn urge. This started about a month ago, and is still here with me to this day. I also remember having this a couple of years ago, but not to this extent. But like many others on here regarding this, I am one of those who doesn't get it when I'm sleeping, I have had a hiatal hernia for over twenty years and have been on medication for it for as long. And so on and so forth. Anxiety? I've had lots of stress in my life being a school teacher, but in the last few years teaching has been a real treat, so if it's anxiety and it's not from teaching, then I have no idea from what?
The only thing I can think of for myself is the fact that I turned my live upside down, like you did, but for me, it's what caused it.