I was playing as White and felt that the pivotal error early on was preventing b5 with a4 on move 11 instead of Bc1g5. To make matters worse, I missed the opportunity again by playing 13. a3 and he was able to bust up my queenside. By move 18 I was sure that he'd open up the a and/or b files and bring a lot of pressure by I was able to patch it up before he could do more damage.
My opponent offered a draw on move 33 but I declined because I thought I saw a way to create a passed pawn after playing d4 with the king nearby to occupy d3. He later blundered and resigned before I could attempt this.
So, any thoughts on how black could have won this - particularily from move 18 on? And, on a side note, as a forum noob, how do I post the playable game board into a post?
Link to a game: Game 7381546