I agree with the others. Something’s not right & you need to get to the bottom of it. Just an outside observation – going all out with running hills at 56 years of age (after a hardcore strength training workout?) could very well have something do with what you’re experiencing. I know you see where I’m going with this – over-exertion is definitely a possibility for what’s happening, if not the reason. I can say that because we’re close in age – take it down a notch or two & you should be good. Neither of us are in our 20’s anymore, but we can still train hard while accepting our limitations that Mother Nature is forcing on us. Good luck Malik.