if you are on anti depressants, it causes dry mouth.i had that for the 1st few months of being on anti depressants. back pain is because your muscles are constantly tense, and can also cause sever stomach pains. I thought my appendix burst, I even had blood drawn and went for scans but nothing. it ended up being anxiety, just because I am scared of dying of my appendix bursting. or even having a heart attack. im scared to be alone, even when I take a shower because im scared I have a heart attack and no one can help me.