Anxiety, advice is needed

I am 3 months PP and lately have had all of these random symptoms like itching and today some shortness of breath and chest tightness. I'm sure it's allergies and I took Claritin but I get so much anxiety!! I keep getting scared like what if something is seriously wrong with and what would happen if my girls grow up without me etc etc. I start freaking out which of course makes my chest tighter... Anyone else have this anxiety about dying and leaving your kids? Anything help? I am already taking Zoloft for depression. I just hate this feeling of anxiety where something is wrong with me.....Then I feel depressed for feeling so weak