I also realise that it has nothing to do with the task's characteristics really i.e how boring or interesting it would be otherwise. It has to do with how much mental effort & time the task will take.

But it doesn't feel the same as being overwhelmed feels, at least being overwhelmed to me I imagine is like really overloaded and lots of pressure and chaos, though I don't often feel this but I have for short times (I prioritise fast so I don't really have that issue)

Pressure overall is ofcourse a problem too when I know I got too much to be done fast enough or whatever obligations are there that are too many but that again feels different. Feeling of pressure feels very different from this feeling.