For the last few days, my heart rate has been higher. i have weird feelings in my chest and throat, palpitations, and i am tired. the cardiologist said everything is normal. what should i do?

Anxiety : Common symptoms of anxiety. An underlying physical cause should be evaluated for, at least by a medical & family history & performing a physical examination. Labs, chest x-ray, ecg, echocardiogram, holter & event monitor are often negative & may not be needed. Thyroid & other endocrinological disorders can sometime manifest this way. Discuss options with family doctor or internist.

Agree with cards: Not much info, but if the cardiologist said heart is normal i think you have to believe them. Your symptoms certainly do not sound cardiac nor do we expect to see cardiac disease in someone your age.

Tachycardia: Heart rate greater than 100 beats per minute is considered tachycardia. If you have this there are a number of reasons that could be causing this. I would start out by cutting out caffeine or anything else that can raise your heart beat. Go see a doctor they may give you a monitoring device to make sure you don't have any weird arrhythmia. Anxiety/stress can also cause tachycardia as well.

Anxiety: I am happy to hear you saw a specialist. The most common causes include anxiety and caffeine use. Discontinue coffee, tea, soda, energy drinks, and any supplements. The anxiety component could be common depending on what is going on in your personal life. School, work, family, significant other. Try increasing hydration, mediation, and possible counseling.