You hit it right on the head, you are depressed, suffering from anxiety, feeling lonely. You have come to a good place to vent and get some ideas.
Sometimes doing something as silly as cleaning out your purse, or a drawer can distract your mind from thoughts gone wild.
Exercise, if you run or something like that will help.
Deep breathing, when anxious people, tend to breath shallow, and carbon dioxide builds up, then they don't get enough oxygen, and feel like they can't breath. Also a problem in the car with the windows up.
Maybe this, take a nice shower or bath, shampoo your hair, put something clean on. Lay down on your bed, with some music on, maybe ear phones, do the slow deep breathing, "smell the roses, blow out the candles", visualize it. Think of the number 300, count back 3, 297, count back 3, 294, gets harder, have to concentrate, the object is to slow down and change your thoughts.
Make an appt at the doctor. Seriously, you sound, upset and depressed. Need some help. The blood tests tell the doctor alot. He can advise you from there.
Call the doctor.
Hope that helps a little.
You can vent here whenever you want, say whatever you want. ts OK. People here care.