umm i missed fort ranik and barradin estate.. and now im in post apoloclypic world..

omg i probably missed a ton of quests.. what do i do!!!

cant go back unless you want to start a new character.

Well, you could delete your character and start again...
Or you could just forget about them and get on with the game. It doesn't really matter. Anything you could have found in pre-searing will pale in comparison to the stuff you can get in post-searing.

You missed out on about 1000 experience points and probably about 2 hours worth or running. Consider yourself lucky. As long as you're mid 6 or seven by the time you get to Post Searing you'll be fine.

Just continue to play your current character. When you have ascended, cleared the underworld, beaten everyone in PvP, and you feel ready to start another character, be happy that there are some quests you haven't tried before.

You are not missing anything by skipping the pre-searing quests, other than the fun of solving them (and a bit of exp you can get faster later).