Hi,
I read your post with a lot of interest and felt I needed to respond. About 15 years ago, at the age of 35, I was probably in the grips of an eating disorder but did not recognize it as such. I had to learn to eat again. The panic as the pounds can on was unbelievable, but I'm sure you know what I mean. I'm 5'5" and my ideal weight is between 161 and 176 pounds. I have had several body fat percentage tests and they all come up with the same ideal weight range. I have a very heavy bone structure and I put on muscle very easily and I can become very muscular regardless of reps and weight.
I have lost 55 pounds in the last 2 years. I started at 256 pounds.
I had to do a lot of research to find the information I needed to change my body. I have learned that "metabolism" is somewhat of a mystery to most people. Metabolism simply means the rate at which your body uses energy. Since muscle is the big energy user in the body the amount of muscle you have determines the amount of energy you burn. When you say that you have messed up your metabolism, as I did, what you are saying is that you have lost a lot of muscle tissue as a result of extremely low caloric consumption. I have lost most of my weight through the process of regaining my muscle.
Aerobic exercise trains the fat cells to release stored fat. Eating too few calories trains the fat cells to store fat. For a detailed explaination of this process I will refer you to a video program called Fit or Fat in the '90's by Covert Bailey.
Do not worry about gaining weight. The processes that "messed up" your metabolism can be reversed.
Also, I question how anyone can know that 2000 calories is an appropriate amout of calories for a person without knowing how many pounds of muscle that person maintains and how hard those muscles are being worked.
Good luck to you in your recovery.
Carmen