I feel like I need to retreat into my shell as if I was a snail, how to I translate this?

I've had this feeling for the last hour or so that I need to retreat into myself. Akin to a snail retreating into its shell, I feel like I need to collapse into my own chest. I guess I could also describe it as a whirlpool that I'm unconsciously resisting but need to get sucked down.

I dont know what this means or how to satisfy this. Any advice would be great.

I suppose for context, I've just finished 4 days at work after a rather regulating weekend away (minus some patchy sleep). I have a good job, I enjoy it and the people I work with, but I feel so drained already. I noticed a decline each day coming back (great mood after day 1 to battery depleted to a barely functional 10% after today)