I looked it up in my Oxford Dictionary and Thesaurus, edition 1996, which resides on the second shelf above my desk. I saw thus is an adverb. Therefore, the -ly suffix is a bit redundant. Nevertheless, I kept looking. Ah ha! IT IS A WORD! It is listed as a colloquial adverb. It has made it into modern usage and is listed as proper.
Thusly, it is fine to use THUSLY.
And February 11 where you are!
Thusly is a word. It does look funny, though. I will be using it more often ‘irregardless’ of how it looks. The brilliant part on my end is definitely misplaced. Did you see my post to you last week on not being able to help my kindergarten grandson with his homework? And I don’t know how to do italics, either.