The right sentence is the first one, and the meaning is: Starting from now, you don't realise true happiness until you have it.
The second sentence doesn't make sense for me in that way.I'd write it in this way.
You would never know true happiness EVEN you have it. (present and future)
You would never know true happiness EVEN you had had it (past)
But you need a master in English answer because I'm not a master....