Hmmmmm, I'm not a fitness coach, but do you think you are working out too much? If you are not able to eat many calories, and then these long walks and work outs, you will stall some. I am sure you already know muscle weighs more than fat, so there is that as well. You may be building muscle, so do not see a decrease in the scale.
Do your clothes fit more loosely? Maybe that could be a victory to keep positive and help up your mood.
Best regards
Di