Help with my plateau please

I was loosing weight pretty well up until a month ago. I lost about 40 pounds. I was losing about half a pound per week even though I had myself listed at 2 pounds per week on the caloric limit. For some reason the weight-loss had slowed down. I was also feeling somewhat rundown and tired. The recommendation was to potentially just jumpstart the system by increasing my caloric limit by just changing my setting the goals and listing myself as loosing half a pound per week instead of 2 pounds per week. I definitely feel like my energy has come back and I have been able to feel more energized. I have been doing calisthenics and recently increased rep range and thought that this could be an increase due to muscle gain. If I list myself and losing half a pound per week my current height which is 5 feet 11 inches and weight of 212 pounds my caloric range is about 2100 cal. When I had myself set at 2 pounds per week I was eating in the range of 1350 cal. I would usually add back the exercise calories in those settings so I would range slightly above 1350. I usually exercise burning about 700 cal per day. I do this by doing aerobic circuit training calisthenics - things like the insanity workout and my own additions of push-ups pull-ups and shoulder exercises as well as curls and tricep dips. My goal is to reach 180 pounds. Over the last month to six weeks I have not really lost any weight of been sitting in up-and-down pattern around the same 210 lb range. I i'm not sure now that actually increasing my calories to trying to lose only half a pound a week had any significant benefit on my weight loss and whether it may be extra considering to potentially a weight gain. I'm a little frustrated and confused as to how to break through this plateau. Any ideas or information would be much appreciated. I should also mention I have changed up some of my activities since it being summertime and all. I've added hiking bike,riding bikes to my regimen so if anything I was actually burning more calories now than I ever have previously. I do not eat back all of the exercise calories either. There are sometimes when my neck calories are only 900. This is one of the reasons that I actually increased my caloric range too 2100. Any help would be much appreciated especially from all those with broken through those plateaus and lost in the high ranges of 80 or more pounds. I say this only because I pay total would need to lose approximately 70 pounds from my original weight. Some of your weight-loss numbers on the forms are amazing just the sheer quantity of weight lost his quite impressive. Please share any techniques.