Ryan Lochte is celebrating his sobriety ... admitting he fell into a "really dark place" a few years ago -- but after checking himself into a rehab facility for substance abuse issues, he's doing better than ever.
The 41-year-old Olympic star opened up on his struggles in an Instagram video ... in which he revealed he's 54 days sober.
Lochte explained his journey ... saying he struggled in the aftermath of a serious car accident when he crashed into a garbage truck on his way to pick up his kids from school in 2023 .