@dimlylitmonkey: you can find info (and a solution) for the Double Shovel glitch in this website:

http://zelda.wikia.com/wiki/The_Legend_of_Zelda:_Link%27s_Awakening_Glitches

where it says:

Having the bow, shovel, and boomerang consumes an extra space in inventory. If Link does this, he will have to exhaust his supply of powder (or possibly bombs or arrows) in order to make space in the inventory. The magic powder is not vital until towards the end of the game, so it is easy to miss the error (which results in the game becoming unbeatable).

If Link goes to the beach and trade back, and if he has bought the shovel since trading his first one for the boomerang(i.e. to unlock the ability to buy the bow), he will now have two shovels.

I hope this solves your problem; I have had a similar problem with the last Zelda game for DS, and I got stuck in a dungeon. THAT WAS BAD, I had to sell the game without seeing the end, after playing more than an half of it...