Those Spring and Summer Challenges should really help you have some planned activity regularly.
If you haven't already done so, you might want to add some measurements other than weight on the scale. Waist, Hips, Thighs, Calves, Ankles, Neck - we can lose fat in seemingly random places sometimes. I know there were times when my face or even shoulders were where I'd suddenly notice a difference. Those can be a boost even if the scale is being less friendly.
Also, any time you notice an improvement, write it down somewhere. Non-scale victories can be very personal sometimes, and some are real surprises because we don't even realize how much we adjusted for the weight. As you get further along in the journey, keep all those readily available for weeks you're feeling down to remind yourself of how far you've come and where you don't want to go back to.