hi joerthinam
I can only speak to ptsd and panic disorder. ptsd is an anxiety disorder as well. you can look up the dsm criteria by googling it. something traumatic happening in your past causes ptsd. you typically have flashbacks and dissociation with it. this often leads to the anxiety. again, you can look up panic disorder's criteria by googling it. you typically fear you are going to die. you are afraid to do things fearing you are going to have a panic attack. I am sure you know the symptoms of a panic attack. both can be very debilitating. all I know about cfs is it is very tiring. no energy. I don't know that anxiety comes with it. welcome to psych central. you will find we have several forums where you can post about your concerns and receive feedback from other members. you will get a lot of support here. again, welcome