Pasta for lunch just means salad for dinner to me. You have to learn to adjust your intake to fit your life. Pasta happens, parties happen, holidays happen. You adjust accordingly. You can't panic every time you do something you feel is wrong. You simply pick yourself u[ and get back on track. If it happes too often, you start examining the WHY- is it something in your past haunting you? is something "too" available? are you not making time in your life to succeed?
This is a journey of discovery so you need to do what will be possible for the rest of your life. Freaking out over pasta isn't an option.

Sorry if this sounds too rough. I've just seen so many people recently freaking out over what they feel is a poor choice. Beating yourself up doesn't get the job done. Naturally thin people don't freak out when they eat a piece of cake, they simply naturally adjust their intake or their activity over the next few days to compensate.