It may well be a sign of depression, but in my opinion depression is a natural reaction to life..When you experience the absurdity of everyday humdrum, you see through all the nonsense and see life as it really is...meaningless, random and, well, absurd...but carry on anyway, see what happens.
The journey... enjoy the journey... the end of anything is rarely the fun part.
It's not meaningless. That's why there's so much smoke about what comes before and after: the implications for RIGHT NOW. If that has become tiresome to you, it reflects in no way on life.
Your a long time dead. So you might as well do stuff while you still have the chance.
To make life before death at least bearable.