I feel my heart pounding with a little dizziness, am I having a heart attack or a heart problem?

My name is (—-) and I’m 22 years old. For the past few weeks I have been feeling strange. My heart is pounding like if it want to jump out of my chest. It lasts a few minutes and it stops. It happens a few times per day. On some days zero. I also feel dizzy sometimes. I also have been stressed lately and having sleeping problems. I sleep bad. 4 or 5 hours per day. Normally I sleep about about 9. Do I have a heart problem? Is this a heart attack?

Age: 22