Frustration

2.5 lbs per week is quite high (it comes out to 10lbs a month or 120lbs a year - that is not something to sneeze at) And getting discouraged after two whole weeks is a little silly - this will take time. Be patient, have faith and don't quit.

There are two reasons you might be comparing yourself to last year-- either you lost some, maintained, and now you're back to lose more or you lost some and gained it back. Either way there's a simple explanation for why things are slower this time. If it's the latter and you're lighter now than you were then, it's just a matter of not being to able to burn as much fat at a time because there's not as much fat to burn.

If you're in a pattern of yo-yoing you'll likely find that each time you try to lose it gets harder. The first time you sacrifice muscle by doing what you're doing now- impatience and trying to lose too much too fast. Then when the weight comes back it's almost all fat unless you're lifting weights and eating a lot of protein. When you try to lose again you can be the same weight but now your body fat percentage is higher than it was last time. That means your maintenance calories are lower and you'll look larger at a lighter weight as well (muscle takes up less space than fat).

Set yourself up with a reasonable deficit. Keep doing what you're doing to protect your muscle. Be patient and make sure it sticks.

I've actually gained after starting a new rigorous workout program. Your muscles can retain water at first so be patient with it. It is annoying though when you work so hard and you don't see that scale go down. I also know that the TOM will add water weight to me every time.