You deleted your post before I had a chance to reply. I hope this gets you so that you know that you are not alone.
Hi sweet heart : ) I am currently going through the exact same thing. We are even the same age. It started almost randomly for me and I could have sworn I was having a heart attack. My heart started pounding I was sweating my chest and arms felt funny and I felt like I was going to pass out. It has been really hard for me to accept that this could be anxiety or is related to anxiety. It is so hard for me to be alone lately. I went from being a very independent person to not being able to fall asleep and having attacks at night time that completely drain and scare me to death. My whole life is being consumed and much like you my mind trails off to waiting to die or feeling like I will die soon.
I am so sorry that you are going through the same thing. If I could take the feeling away from you I would in a heart beat, I completely understand you.