you're not crazy
the PhD is structurally lonely in ways undergrad never was. cohort shrinks; advisor is busy; peers are in different fields; partner hasn't read your chapter 4 draft (and shouldn't have to). 4-7 years of holding a research question in your head while everyone around you doesn't quite know what you're doing.
the 2am panic hour: chapter 3 won't converge, conference deadline in 9 days, advisor ghosted your email again, and the imposter-voice is louder than it should be.