I have lost my self in the nether and can't find away back to my portal. How can I save myself from sudden Doom?
Do you have cheats enabled (or are an op if you're playing on a server)? If so, you'll be able to kill yourself while keeping your inventory. First step is to set the rule for keeping your inventory:
/gamerule keepInventory true. Second step is to kill yourself. You can try
/kill, but since you're in the nether, it's probably just as easy to jump in some lava.
Unfortunately, if you don't have cheats enabled, things become a little more difficult. The easiest way I know of is to craft a chest (you did remember to bring some wood, right?), put all your stuff in it, record your location (press F3 and look for the line with the
z), and then proceed to kill yourself. Get geared up again, and head back to the nether. Once there, simply head back to the coordinates you recorded earlier. You may also want to bring some rail and obsidian, as the nether is a great way to get around your world quickly.