Born and raised in Indiana ... I remember toughing out the Winter days.
Dreading the first snows.
Upset at the "drive to work in the dark, drive home in the dark" time change.
Refusing to go outside because the cold cuts right through my clothes, no matter how many layers I put on.
Getting cabin fever after about a week.
Being in a semi-homicidal simmer for the rest of the time until green leaves started to show on the trees.
Now I live in Florida. Happy as the proverbial clam ... except when my company sends me north for jobs. <They don't know about my Indiana days, I think.>
All that said, it does cool down, a bit here. One thing I see quite often is your comment on water temps. "It will literally jump five degrees overnight." This is not quite correct. SURFACE temps can vary that much. Deeper than an inch or so, and water temps take longer to change. Find the deeper holes and concentrate on those. Water temps are more consistent, and the fish can actually hover up and down to find their comfort zone.