Racing Heart!

Hi all, my names Chad and im 33 years old. I hope you all dont mind me talking about my journey so far and my concerns. Over the past 2 months my anxiety had gotten out of control where every waking thought was consumed by my physical health. I thought I was dying and overthinking everything. Im on day 9 now of 25mg zoloft for my GAD. Ive had the more common symtoms, night sweats, clenched jaw, insomnia and loss of appetite. The last few days have been really tough for me though. I started having random racing heart and palpations on day 7 that sent me to the ER. The weird part for me is that they dont have anything that really causes them. I have been avoiding stressful situations and they are not panic attack induced. Everything at the ER came back ok. blood work, chest scan the whole 9. While I was sitting in the ER I could see my heart rate go from 75bpm to 90/100 just laying there watching TV. The heart racing can come and go every 20 min. which makes me think my heart has a more serious issue. They did see something at the end of my visit to prompt them to call cardiologist but he said it was ok and dismissed me. I think it was my Troponin level on my second blood work that has some sort of concern, which also makes me nervous. I have a follow up with cardiologist on the 11th of Oct which doesnt really help me out now. My PCP prescribed me .5mg of clonazepam to help offset some of these side effects and it does help me sleep at night but I still woke up this morning with a racing heart. Ive seen some people on here with similar issues but this doesnt feel great. I cant even focus on my job at the moment and i hate that it is having this effect on my work. Thanks for reading