Seems

like its always a struggle.

One goes a lil down the other one starts rising.

Then vice-versa.

It's just life happening.

Even if I did have to replace the furnace?

Plenty of worse things that could have happened.

Goes back to:

"Under stress, ISTJs may fall into "catastrophe mode", where they see nothing but all of the possibilities of what could go wrong. They will berate themselves for things which they should have done differently, or duties which they failed to perform. They will lose their ability to see things calmly and reasonably, and will depress themselves with their visions of doom."

Mom is the same way.

Worse actually.

Over much smaller issues.