So, my name is Niklas and I'm 19 years old from Finland. I used to be working out many times a week and I was in extremely good shape and life felt good last summer and early autumn. I had horrible tooth pain that I had been hiding from my parents and I was taking painkillers. One weekend the pain was so bad that I had to go to the dentist without and appointment. I was super scared and I felt like I wouldn't see tomorrow for some reason. I had to wait around 3 hours at the dentists office before getting in. My whole body was shaking and feeling cold. I finally got called in and they got my wisdom tooth out super fast. I felt happy and relieved. They told me not to exercise for few days. (I was used to working out around 5 times a week) I got home and watched some Netflix for few days because I had nothing else to do. After 3 days I noticed that my heart rate was around 80 when I was just sitting down. I got really worried about myself because I couldn't understand what could be wrong. I rested few days more and it just didn't go away. I went to the gym because I thought it was just some kind of stress. After jogging slowly for a bit, I noticed that my heart rate was already at 150 but I wasn't out of breath or anything. That freaked me out and made me feel dizzy (probably because of anxiety). I went to a doctor next day and took some tests like EKG and everything was according to them. For some reason I didn't believe it. I've been crying few times because it feels like I can't get over this obstacle and working out is a really important thing for me. The dentist appointment happened on October 2nd and I'm writing this post on 4th of January. I've worked out only 2 times in that time. Lately I've been avoiding even carrying grocery bags to not raise my heart rate. I have been checking my pulse at least every 10 minutes. I've also been avoiding going out with friends even if it's just a lunch. I haven't really been able to complete my high school courses because I have been absent a lot. My anxiety has been getting worse and worse. I have an anxiety disorder and I've experienced panic attacks before. I used to take meds for that but I stopped around one and half years ago because I felt like I was ready. I've experienced depersonalization before when getting a panic attack but next day I've felt normal again. Last Sunday (29th) I was on a walk with my father and I got a panic attack. This time I experienced depersonalization and derealization and it didn't go away. Since then I've been feeling like my body is not mine and whole world is just something my head made up. I've been feeling like I'm going crazy or something. My parents are supportive but they don't really understand how I feel, which I understand completely. Right now I feel hopeless because I don't know what to do. Should I just try to ignore all this and is there anyway to do a "reality check" to remind myself that this is real? Thanks in advance.