I'm something of a nihilist, but with that I've lost is the reason to care about stuff, even myself and my loved ones. Why should I care about anything?
There is an interesting and much-discussed piece by Richard Hare called "Nothing Matters", in R. M. Hare, Applications of Moral Philosophy (London: Macmillan, 1972), pp. 32–47). Hare develops the point that 'My wife matters' does not have the same sort of logical grammar as 'My wife chatters.' The idea is that chattering is something that my wife does to or at me, whereas mattering is not, in spite of the fact that 'My wife chatters' might be said when my wife chatters to me. Mattering is not like a sort of radiation, like invisible blue light, say, only more rarified, which my wife emits. A lead shield between me and my wife would not prevent her mattering to me. There are difficulties, certainly, with Hare's non-cognitivist approach, but his piece might be the best place for you to start.