Struggling to name those heavy, vague feelings is the worst part. I sometimes copy lines from books into a notes app just to have something that fits. One I keep coming back to is from Virginia Woolf's 'Mrs. Dalloway': 'She had a perpetual sense, as she watched the taxi cabs, of being out, out, far out to sea and alone.' That image of being unmoored and distant from everyone else nails it for me. It's not about sadness, more like a profound detachment.
Another is from 'The Bell Jar' by Sylvia Plath, the fig tree passage. The paralysis of choosing between futures, watching them all wither—that's the stuck feeling. It gives shape to the indecision and fear that comes with it. I don't look to quotes for solutions, honestly. I look for mirrors. Finding a sentence that says 'yes, this exists, and someone else put it into words' makes the weight a tiny bit easier to carry, if only because you're not holding it in silence.