What's the point of being alive when you aren't living?

Not a throwaway.. I am contemplating suicide. the only thing that stops me now and that has stopped me is the fact that I have children. The youngest is 18. Wouldn't they be ok after awhile? I've had a parent die and I'm ok with that, now. Why shouldn't I take my own life? I'm just really tired and honestly, I enjoy nothing so why bother? Anyone else ever feel like I do?