Engine worn out? Oil and Coolant consumption

My 2005 Suburban has been using about a quart of oil every oil change. Recently, I
noticed the temp gauge going up at idle and returns to normal when driving. I checked
the coolant reservoir and it was empty! I put a gallon of new coolant in it and so far it
remains at a good temp. There is no milky gunk under the oil fill cap, the oil on the
dipstick is a nice dark brown/ black, no smoke from the tail. Are these just signs the
engine is worn out? It runs great!