Hey my resting heart rate has gone up(I’m 18 and 308 Lb)

So a couple of weeks ago and I took a ekg because I was having a chest pain,jaw pain etc, and the test came back fine but and my blood test said I have high cholesterol and I’ve been trying to eat better but now my heart rate is getting higher and my anxiety is through the roof! I took multiple test earlier it was around 90 and 100 now it’s 98 to 120 idk what it is but it’s not resting at 100 do you guys know what it could be I think I’m scared and I don’t want my health to get worse coming from people with the same heart rate how did u get urs down?