Kittle and the San Francisco 49ers were dropped in SB LIV by the Chiefs in heartbreaking fashion earlier this month ... and the All-Pro tight end took the loss pretty hard.

Cameras caught the guy on the sideline toward the end of the game pissed off ... but, it seems his bikini-clad wife, Claire, and some Mexico sun are helping him get through the rocky times.

Kittle, some of his Niners teammates and their significant others made the trip to Cabo earlier this week ... and it looks like they're all having a blast.

There's a boat ... bikinis ... some drinks ... and it definitely appears the bad Super Bowl memories are fading away quickly.

"A lil love & a lil sun cures a lot of things," Claire said of the trip.

Of course, when Kittle gets back to California ... the Mexico sun might not be there -- but at least he'll still have Claire!!!