Mike Holston -- a popular influencer better known as "The Real Tarzann" -- was badly injured in a skydiving accident ... and he shared the news in a series of Instagram posts.

The social media star -- known for his ripped physique and his posts involving wild animals like crocodiles and big cats -- shared a photo to his Instagram story in which he was laid out on a hospital gurney.

While Holston wore a neck brace, he did give the camera a thumbs up ... clearly trying to put on a brave face.

Clips taken of Holston show he's clearly feeling the sting from his accident ... swearing a few times before saying his pain's more manageable now than hours before when he couldn't even breath.

In a follow-up clip, Holston speaks directly to his fans ... telling them he's doing alright -- though he hasn't yet said exactly what happened to him.