I don't know what's going on

I am spiraling again. I can feel myself falling,.. I have this knot in the pit of my stomach that just will not go away. Like a big ball of black energy just being squeezed tighter and tighter. I need it to stop. It's making me feel like I am on the edge, Like I am just about to have a panic attack. My nerves feel raw. Like they are on fire. I just want to scream and never stop. i want my heart to stop beating,... my lungs to stop drawing air,... I want my body to stop living altogether,...

PLEASE make this feeling go away,....