My bodies starting to fight me

I'm not sure but I feel like my body is starting to fight me and the weight loss.  I can't really explain it but I feel like the weight is not moving this week.  I switched to oatmeal for breakfast this morning and it did help fill me up and keep me feeling full.  I ate the left over stir fry for lunch and a bar-b-que roast sandwich for dinner with salad and baked fries.  I did snack on baked chips but just ate a serving.  I did get a 30 minute walk in but my joints are sore today.  What is disappointing about that is that the pain has been gone about a week without medication.  It's wet and cold outside and maybe this is playing games with my head.  This weekend should be warmer so we will see if I can battle trough some of these problems.