Why can't I control my heart rate?

[Rexman10000]

Hey guys my name is Rex. I'm 17 yrs old and I weigh 165 lbs. I'm a wrestler and I have always been a great athlete. About two months ago, I was cutting weight by running stairs and all of the sudden my heart rate went through the roof! I didn't know what was happening but my first thought was,"I must be dehydrated." I made weight but ended up not wrestling that night because I didn't feel good. But I got over it because I decided to go up in weight instead of cutting, so I thought the problem had gone away. However, one night I was eating, took a bath, and my heart rate was again very fast! I couldn't control it. I called 911 because I was scared. They told me it was anxiety. My blood pressure is usually low bc I'm athletic but it was very high. So I continued to wrestle but the problem continued. I ended up quitting wrestling bc I didn't want to become a detriment to the team. So two weeks later I decided to run again (keep in mind, I usually exercised 6 days a week. I wrestled Mon-Fri and ran about 6 miles on Sunday.) So I tried to do the usual route and AGAIN my heart rate went crazy. I called 911 again bc I was in the middle of the woods and didn't know what to do. They told me my heart was fine and I just needed to calm down. They also told me I was low on potassium and my kidney function was strange. I haven't had my kidneys checked but I have had my heart checked. I really think that this is just anxiety but why can't I control it? I have this lump in my throat, I feel tired and light headed, and it always seems like I can't get enough oxygen, like I'm always yawning. And they say exercise helps but when I exercise my heartrate goes way up.  Idk what to do! It's like there's no right answer. I want to wrestle and be the Christian leader I have to be but with these issues it's hard to do what I need to do. Wrestling, running, and weightlifting used to be my life and now it's like I'm scared to and like I don't have motivation to anymore. Please help me out and I really appreciate it.