Minecraft Help

[MintzMachete]

So i have been playing a lot of minecraft in the last few days... finally got obsidian.

So I make a portal. It brings me high above the ground in the nether. So I move 300 blocks away. Same portal. So i put my stuff into chests. Go into nether and break portal. When i go back to nether from the three hundred block away one it brings me way above ground aswell. What to do?

Thanks, Mintz