UGH! Help!New Mac owner and I'm about to throw it out the window! Won't stay connected wirelessly to the internet.

I purchased a MacBook Pro 13":

Processor 2.8 GHz Intel Core i7

Memory 4 GB 1333 MHz DDR3

Graphics Intel HD Graphics 3000 384 MB

Software Mac OS X Lion 10.7.3 (11D50b)

I have AT&T DSL with the 2wire wireless connected directly to the dsl line. There is no base computer. I owned a netbook prior to this and had several people use there pc laptops wirelessly before. Now I can't seem to get my Mac to stay connected wirelessly. My iPhone 4, touch and satalite still maintain perfect wireless connection as they did before. I called apple , they said it was my internet, I called AT&T they said it was the Mac. I have a similar post on AT&T, hopefully someone can help! This is NOT how I wanted my first Mac experience to go!!! It is vital I stay connected because I remote in to work constantly and can not be interrupted. Someone PLEASE help!!