You even need your wins analysed. :P

a4 and a5 are designed to weaken your (allready weak) kingside. After a6 b6 Qa3 your a pawn is lost and white has significant pressure on your king down that file, particularly with his bishop dominating on d4 allowing for his queen to come to c6 or b7.

After 6 moves you do indeed have a better position, but that is only because white made a mistake.  He or she failed to use the discovery (a very powerful tactic) to its full advantage.

White should have played 6. Rxe7.  The queen is forced to move (or else it will be lost for a bishop after Qxb1 Rxe8+ Kxe8 Qxb1), and the rook should be able to gobble up a second pawn on either b7 or g7.  After that your position is falling apart and white is still quite comfortable.