Uncomfortable feel and pain. Steps.

I am 36yrs female and have 2 kids. When I was carrying my second baby in yr 2016, I had lot of discomfort related to heart, often it use to pain n my left hand always pained. It my 4th month pregnancy I did an ecg n found things were normal, since I sleep more on to left it was only muscle pain in hand. I was scared because prior to this when I did ecg the report said low heart rate. Now from past couple of months I get pain in left chest which lasts for few minutes and also my left hand pains. Sometimes the jaws feel uncomfortable as if I have to take the knuckle out to ease it. I am scared because my cholesterol was in border line but I took up keto diet in between for 2.5 months and after that when I did a health check, my results of ecg said low pulse rate and cholesterol had reached high risk level. I take 25mcg thyronorm (which was prescribed in my pregnancy time) tabs as my thyroid was high. Kindly suggest me appropriate steps.