I hate to hear the self doubt!!! My friend struggled with her "set points" convinced that she was destined to stay around 190. She let that thought overwhelm her and it brought her weight up by 15lbs. She has been stressing about it and recently started to evaluate why she was gaining. It all came downt to food and exercise. She was still eating Atkin's food but she was eating a lot of food and she hadn't been exercising. I think no matter what you are doing portion control, calories and ultimatly what you are putting into your body play a big part in helping to lose weight.
You have been exercising and you have lost a lot of weight so as you get closer to your goal weight it gets harder. Your body isn't shocked by what your doing to it anymore. It needs a jolt and when you mentioned cheat days I wonder if they are more of a threat to you than you let on. Cheat days have ruined weeks of progress for me... they are usually the reason I stall. I could, if I let myself, get myself back up to an average of 2,000 calories a day just by letting go on a cheat day. They are bad things in my mind. You shouldn't need to "cheat" in your diet. You should let yourself have things so you don't feel deprived but just have a little bit. Like the 3 bite dessert rule. Order any dessert and just take 3 bites... easier said than done I know.
I am hoping this isn't coming off as lecturing because it is not meant to. I am sad you are so frusturated and you seem to have given us clues as to why you are stalling. I don't believe for a second you have a set weight at 185. It stresses me to hear it because it's like saying "it's ok to be there because my body won't do anything else". Look at what your eating, remind yourself of your goal, look up some new workouts to do.... (though I think that you are fine on working out).
I hope your wieght will start going down again! I hate to see you come so far and then lose hope! There are so many good things that you have done and acheived and you can totally get to where you want to be if you don't give up!