Buy bathroom scale.
Step on scale once in a while.
If the number keeps getting bigger, actually go to the gym you joined as a New Year's resolution.
Exercise really does not help.
There is at least one exercise that can help.
"Push-aways". From the table.
Losing weight is a lot harder than gaining it. Been there, done that. People that want to lose 25 pounds want to do it all in a month, when a pound a week is far more achievable and won't kick your body into starvation mode.
Control portion size and trade your potato chips or ice cream for an apple, there's 250 calories a day less. Burn the other 250 in the gym, and there's your pound a week.
Base metabolism is important, but you can change that (slowly) over time by being more active.