is common with a stressful life and hence commonly causes aerophagia
i.e. increased air hunger. Because of that a lot of times you will feel lethargic and yawning. Also if you drink a lot of tea or alcohol then cut down on it.
Its nothing very serious but its a common thing seen in army people once they get deployed or retired. A serious condition is called a dacosta's syndrome. But it doesn't look like that so just relax and start some recreational exercises or see a psychiatrist