A deep numbing pain

Sometimes before I try to sleep I get this strange feeling that floods the front of my chest near my collar bone. It feels like something is weighing my lungs down and it starts to induce a panic attack.  Even if I try to stay calm and ask myself, " ok what triggered it? should I even be crying?" it still washes over me full force and I end up losing hours of sleep.Has anyone else ever had this kind of feeling before?