Welcome. The only way I am able to conrtrol my sweet tooth is to not buy the sweets in the first place. If they aren't in the house, I don't eat them. If you need sweets how about some strawberries or other fruit.
For motivation we just started a 4 week challenge to keep our selves in check through the holidays. The basics are to set weekly goals. My goal this week is to "workout" 5 days for 30 mins. By workout I mean ANYTHING! Play a game of tag with that baby. Maybe try a video at home. The 30 day shred is a Jilian Michales video and is only 20 mins. It is a solid kick your butt 20 mins, but it is more activity than I have done in the past and I usually have 20 mins of energy after my day.
Why don't you pick a goal for the week and let the board know. Having to be accountable will help! GL.