17 and I feel like I'm going to die

Hi there I'm a 17 year old male who is scared that they have a heart problem I have convinced myself that I have heart failure or atrial fibrillation I believe I have this because Everytime I do light activity I have my heart rate shoot up like to hundred range or 180 like I stopped playing soccer for like 6 months and then when I went back to play I could still play unitl one day I did marijuana and I had a panic attack that was my worse day ever and from there I have been having chest pain and rapid heart rate with little excercise . I went to the doctors they said everything is ok I'm fine but I just don't believe them because I feel like total s**t . I cry sometimes because I'm too scared  of playing the sport I love SOCCER. This is my senior byear and I can't play soccer Everytime I try i get super fast heart rate then light headed don't get me wrong I'm not out of breath or tired just a little dizzy and fast heart rate. Can marijuana cause heart problems because ever since that bad panic attack I have been having chest pain and fast heart rate please I need help 

Absolutely weed causes this - you may feel palpitations, a feeling of doom, or even a feeling like you’ll never feel the same again. But if your doctors have checked everything out, you gotta believe them! Trust me, my friend went through this - it takes time, THC (component of weed) stays in the body for 30 days (sometimes more in others), so if it takes some time for you to feel better, know that this is ok. My friend believed (no matter what we told her) that she wouldn’t survive the year, and this was completely the later effects of the THC. Not many get panic attacks with weed, which is why I believe that this isn’t as commonly discussed. Plz feel free to PM me, as my friend really benefited from talking through it. 

Dude you have health aniexty same i have if you have doubt then go check by doc i had ecgs and i reported normally i haved overthinked to that much extend that i have developed dpdr so dont do same mistake i did if you have doubt on your heart go get checked

I have but everything comes out fine I feel like I'm going to die from a cardiovascular problem  my chest pain Is always there i just don't know what to do anymore