Can any atheists give me advice about finding something to replace spirituality?

I am existentialist and it doesn't give you a meaning/purpose for life exactly. Rather it tells you that any meaning in your life is what you yourself create, which is what you need to do. It sounds to me like you're quite down about your lack of belief which is quite common really, you're trying to fill a huge hole. You know though, just because love is a biological mechanism doesn't mean it isn't wonderful. Just because no god made that flower doesn't mean it isn't a miracle.