For About A Month I Have Been "dragging". I Am

For about a month I have been "dragging". I am 77 yrs old and in good health, as far as I know. I go for regular check-ups Nothing wrong except borderline hypertension, for which I take cozaar. No other meds. Some supplements, like multi vitamin and calcium. This fatigue came on suddenly and is atypical for me. Sometimes feel faint and shaky. Everything is an effort. Out of breathe after climbing stairs or doing most anything. I plan to see a doctor soon, but have been away all summer and just back home.