Speaking from a medical background, your resting heart rate (based on so many things) should be under 100. I don't get too nervous as a health care worker unless resting its over 120. But, I think that people who have increased stress and anxiety have higher heart rates. EKG showing Tachycardia doesn't show anything really. Have a stress test? That may help show some stuff. I have had one. It's not bad.

Reasons other than stress your heart rate could be elevated while resting: PSVT(Paroxysmal Supraventricular Tachycardia) Fancy big word that says your top chambers of your heart beat way faster and do not effectively pump any blood.
Infection. You may have a small infection that you don't notice. Check your temp, monitor yourself for that.
Headaches. They can raise your pulse
Caffeine. Definitely can raise your pulse
Dehydration. Try drinking some gatorade/powerade to get your fluids up. Drink lots of water also.
Blood sugar issues. Check your sugar if you have a glucometer at home. If not, just watch what you eat. Notice any changes.

Let me know how you are. Take care.