Taylor Frankie Paul is pulling back the curtain on some dark times -- posting a bruised arm pic on Instagram with a message about how emotional scars cut deeper than physical ones.

The 'Secret Lives of Mormon Wives' star shared the photo Wednesday alongside a gut-punching caption ... saying, "The psychological torture damaged me way more than the physical."

She doubled down, adding ... "You eventually become a shell of a human. This is hard to share because it's hard to come to terms with."

Taylor didn't name names or give much context, so it's unclear who she's talking about or whether the photo is recent or from an earlier chapter of her life.

Still, the post dropped not long after she opened up about allegedly being manipulated, threatened, and gaslit -- without directly naming ex Dakota Mortensen, but heavily hinting at their rocky relationship while admitting she's not completely innocent in the legal fallout.

As we reported ... tensions between the pair have been boiling for a while -- and they're still navigating legal issues after TMZ posted video showing Taylor accidentally striking her child with a barstool during an argument with Dakota.