Lil Nas X Exhibiting Erratic Behavior Before Arrest

Yesterday rapper Lil Nas X was hospitalized for a possible drug overdose after his arrest for assaulting a police officer while wearing a pair of underwear and cowboy boots [click here if you missed that].

Video from earlier in the day shows Lil Nas wandering around the streets before taking off his shirt...

From TMZ

Lil Nas X's nearly naked adventure was brewing almost 15 hours before his early morning arrest ... based on a new strange video of him wandering aimlessly around Hollywood!

TMZ Hip Hop obtained this surveillance footage recorded outside the Short Stories Hotel around 1:30 PM Wednesday. Sources at the hotel confirm he was there, although he was not a registered guest.

Still, the video makes it seem like he was going through something -- you see Montero all by himself strolling off the street, and into the hotel's courtyard area.

Unlike his shocking encounter with a bystander early Thursday morning, Lil Nas X was fully dressed at the Hollywood hotel -- cowboy hat and boots, jeans and a short-sleeved shirt -- as he fanned himself.

The "Old Town Road" rapper later found his way into the hotel's lobby, where he hydrated with a cup of water ... and then, for some reason, decided to go shirtless as he walked back on the street.

We broke the story ... Lil Nas X ended up wandering Ventura Boulevard -- about 7 miles from the hotel -- at 4 AM Thursday, wearing only his tighty whitey underwear and white cowboy boots.

It's still unclear what Nas was up to in between the 2 incidents, his camp's been radio silent since the arrest. As we reported, he was booked for battery on an officer ... after allegedly charging at cops who responded.