Phrase "my get up and go got up and went"

‘The old saying "my get up and go got up and went " describes a person with hypothyroidism (low thyroid). The thyroid gland is your metabolic engine, and when it’s not putting out enough juice, your energy goes down the drain. At the very least, get a TSH test, the first level of screening for thyroid problems.’
I know ‘get up and go’ means energy,courage,etc,but what is meant by the old saying "my get up and go got up and went "?

Ksguo, I feel that you have already answered your own question.

Hey, do you know anyone who is going through thyroid problems?

It’s a bit of a play on words. As you correctly stated, ‘get up and go’ here refers to energy, motivation, drive, etc.

So, instead of simply saying you don’t have any ‘get up and go’, by putting the phrase in the past tense, you’re playing with the idea that any energy, motivation, drive, etc. you might have had is now gone.