Fish Out Of Water, Seeks Push Back Into Pond.

I'm sure there's probably an abundance of posts like this already and I apologise if I'm just repeating others, but after a rather vague (i'll admit) look, I couldn't see exactly what I was looking for.
I've been playing the game for years now and like many I've had my fair share of breaks here and there, every time returning to change, gotta admit, this is the biggest change I've come across so far.

I had PLD, WAR, RNG, COR at 75 NIN at 70 and was in the process of levelling DRK. PLD being my main. Within about 5 minutes of logging on I'm told PLD is dead. Made me wonder, what's actually worth it's salt out of the jobs I've got so far to take further and of any use? Don't really fancy putting my energy into something that nobody is gonna need or want.

Also, is old endgame gear irrelevant now in some respects? Whats still good? and out of whichever job I have worth pursuing, what gear should I be looking at?

So basically, I'm looking for a hand to point me in the right direction so I can get back into the game ASAP. Again sorry if I'm being somebody elses lazy echo here! ^^;