I guess I would look at what you are eating. You may have restricted your caloric intake to the point of slowing down your metabolism.

By the way stress can swing you either direction. Dealing with stress - I dropped 18% of my weight and then gained 36% back in a matter of 6 months.

Dealing with a lot of stress now and dropped 10% of my weight. I think it can go either way.

Maybe now would be a good time for a physical? Check to see if all the vitals are working as they should B/P cycle really can mess with the organs.