I agree with what others say - it sounds like you are running a burn-out schedule, and your body has just informed you it is not designed to function that way.

I agree with what others say - it sounds like you are running a burn-out schedule, and your body has just informed you it is not designed to function that way. You must get more physical exercise, more rest, and more switching between 'running and not running'. You cannot persist only on 'running/sprinting' activity, it is like teaching a horse not to eat. It will work for a week, then the horse dies of hunger. The rest periods is the 'price' for it being possible to do the sprints. This is why europeans do things like 37h working weeks. It is because if you want to work a human body for 40-50 years (ie 20 to 70), you cannot operate it in a way that ruins it in one or two decades. Companies like amazon might find it amazing to run people like F1 race cars, where the body stops working after 15 years, but you are not amazon, you a a human ape with needs.