[…] and have been using various Linux distros as my main os for almost 20 years.

Matey. Get into any company that has linux junior positions. You already have more experiance in linux than 90% of the average (windows) Sysadmin.

For realzies now. Most will look weird at you if you ask them to edit a file in the shell or using a server VM that runs without graphical interface.

Get into a linux junior position and get started.

Learn lots and lots. After a few years moneywise you might be back your old job as experienced chemist.