if you use an external editor to design visually, do that, and then go to the “code view”
find the tags “body” one says body between < and > the other says /body between those two angle brackets. stuff between there is your content. you can select all of that, and try popping it into wordpress in the “html” editor view. if it doesn’t work, just delete the post/content. No harm done..
Note: it may not keep all of your formatting. It depends on how your wysiwyg editor is styling the page (which gets more complicated and program-specific than can be explained here)..
what external editor are you using, that might help someone guide you. (to use inline style only)
I’m banking partially on the editor default being pretty ‘stupid’, using deprecated elements – kinda like wordpress wysiwyg. ~<duck />~