Hi IDM,
Yes, sometimes depression can come at you in waves or thoughts/feelings can change like a switch has been flicked. Sometimes fine IS fine, other times it can be more that you've had a distraction from..........or you've managed to convince yourself for that time, sometimes it's depression walking over "what could be".
But maybe if at the times of the thoughts/feelings........you could tell yourself that you are
not going to trust your judgement right now, it is the depression "talking". You might not be able to see/think things another way in that moment, but you can
try to refuse to trust what you're seeing/thinking and
try to hang on in there till..........
Maybe you can try to recall, recall, recall, something/s that made things "fine" before that
without doubting them.
Maybe you can focus on a time/thing that
might make things "fine" again e.g. something that's going to happen...........
Maybe those are times you need to
remind yourself to lean heavily on things that might help
just a bit e.g. if you've got a list (however short!!)..........and that
can include talking to us

I know that sort of stuff isn't always going to help.........but just some thoughts..........
And............"
I am getting so sick of myself"...........
please try to knock that feeling
Fine if at times you feel sick of the depression, but this
is about the depression, it's
not about
you. And while you can be sick of the depression, remind yourself that you are trying to work through it, you have even had some
breakthroughs, and it
can pass.........you have reached/you
can reach "fine"
Alison