I Am 66 Yo Female With Overall Good Health, On

I am 66 yo female with overall good health, on no medications. My work involves keeping others healthy, physical fitness ... so I'm regularly in a gym or walking. In last month or so I have been feeling more and more exhausted, to the point of sneaking in naps! I'm also gaining weight yet changed eating habits. I get 7 hours sleep (though often wake up, toss / turn). My diet is health conscious -- I have had training in diet / food preparation / nutrition. Noticed some difficulty breathing when jogging lately. Very very tired all the time.