Hi there. It does sound like what you are experiencing is panic attacks b/c I had them for years in my 20's. I'm 39 now and have been through therapy and used meds to get them under control. Since I am not a doctor I would suggest you go to the doctor and have all other things ruled out. There are some heart abnormalities that cause the same type symptoms. Now the disturbing thoughts you mentioned may be OCD related if you are having thoughts you can't shake. Thoughts that aren't at all like you so to speak. Is that what you're experiencing? Trust me, you can be fixed. I promise! I went to a psychiatrist who prescribed Klonopin and Prozac, and I was eventually able to get off both. Please seek help from a doctor first to rule out other things. I know the symptoms are horrible, but you can come out on the other side.