You may have an endocrine problem going on.
For example, when was the last time a doctor checked your thyroid function (or have they)? Hypothyroidism, a condition where the thyroid is not emitting the amount of hormone your body actually needs, can cause depression, aching joints, muscle weakness, constipation (which can lead to more gas I think), and hair loss. See PM.
Please consult your physician about these symptoms and ask if they will check your thyroid function, including free T3 and free T4 levels, not just TSH (thyroid stimulating hormone that comes from the pituitary).
I'm sorry you are experiencing this. I know that sometimes extreme anxiety can cause lots of physical symptoms. I am 25 y/o and last year I went through a period of time when I felt awful and would feel physically ill and get a rash. I finally went to my doctor and she said it was anxiety. I did some therapy and it worked wonders. I would go your doctor. Hope you feel better.
You have hypothyroidism. You need a CPC plus all of the T testing. Once your thyroid levels get fixed, you will be great. It will take about 3-6 months. The doctor will put you on synthroid.