Anyone else start feeling physically sick around 4pm on Sundays or am I just broken

Every Sunday it's the same thing. I'll be fine all weekend, maybe even having a genuinely good time, and then somewhere around 4 or 5pm it just hits. My chest gets tight. I get restless but also weirdly exhausted. The sun starts dipping and suddenly the whole weekend that felt so open and free on Saturday morning just collapses into this tiny anxious ball.

It's not even about anything specific. I don't have a terrible job or a boss I hate. But my brain just starts running through every possible thing that could go wrong on Monday. The meeting I'm not ready for, the email I forgot to send, some random task I'll probably mess up. And the worst part is I can feel it physically. Like my body doesn't know the difference between imagining Monday and actually being in Monday. I'm sitting on my couch in sweatpants but my nervous system thinks I'm in the boardroom getting grilled.

I tried explaining it to my partner once and he just said "why are you ruining your own Sunday" and I was like I DONT KNOW THATS THE PROBLEM. It's not voluntary. I'm not choosing to spiral. It just shows up like clockwork right around that 4:30 mark.

Last night was particularly bad. I ended up just sitting on the floor of my living room doing literally nothing for like fifteen minutes. Didn't look at my phone, didn't try to fix anything. Just sat there breathing and staring at the wall like a weirdo. And I guess it helped a tiny bit? But the dread was still there humming in the background the rest of the night.

I dunno. Does everyone deal with this? Is there some trick to not letting Monday bleed backwards into Sunday or is this just what being an adult is now. Not sure I'm even making sense. Felt like I needed to type it out though.