Paralyzing Fear

I am completely paralyzed by fear lately. I am afraid of everything. Everything I see or hear scares me. I am constantly in fight or flight mode and can feel adrenaline coursing through my body. I feel like I am in a closet looking through a peephole watching a murderer walk closer and closer, and just knowing he's going to open the door and kill me. This is pure, primal fear. Xanax alleviates it for a short time but then it comes right back. It is the most terrifying and debilitating feeling I can imagine. Obviously when I feel like this my dpdr intensifies greatly, leading to a feeling like I'm going crazy which makes me feel even more afraid. I just finished tapering off of effexor, could this be why? Everything in me just wants to run to the hospital but I know they can't help me. It is so disheartening to know there's nowhere you can go for help. Have any of you dealt with this feeling? I have tried meditation but it scares me, exercise scares me, talking to other people scared me. I look at my dog whom I love so much and I'm just filled with fear. I can't live like this. To be honest I would do anything to make it stop. Please help.