Jax Taylor is taking time for himself and seeking in-patient treatment for mental health struggles -- this amid his ongoing split from his wife Brittany Cartwright ... TMZ has learned.

A rep for "The Valley" star and "Vanderpump Rules" alum tells us … "Jax has always been candid about his mental health struggles, especially during the past few months on his podcast."

They add ... "He has made the decision to seek in-patient treatment. This is a particularly sensitive time for him and his family. They ask for privacy and respect until he is ready to speak more on this matter."

Mind you, this might not be all that surprising -- on Monday, Jax posted a picture on his IG story with a caption that read "Healing." The post also showed two books ... one titled "Get Out of Your Mind & Into Your Life" and the other was "Set Boundaries, Find Peace."

Of course ... we all know Jax is currently going through a very public separation with Brittany. The two have been together romantically for nearly a decade -- and lately, things have been a bit rocky between them.

As we reported ... the couple began living separately from each other with Brittany living outside their martial home. Our sources told us at the time JT and BC are still taking time apart after fighting a lot over the past year ... which ultimately ended with them separating.

Our camera guy recently got Jax at LAX ... and he told us with everything going on in his life right now, the only thing occupying his mind is his family -- because he hasn't seen them for weeks due to work events. That might be what's at play here with his treatment.