Hello,
Welcome to ehealthforum and thanks for writing
Left sided chest pain can be due to chest pathology,heart issues, muscle strain, intraabdominal pathology such as tender and enlarged spleen,gall bladder problems, pancreatitis etc.Stress and anxiety could also cause similar symptoms.
Usually it is common at young age to have these symptoms due to anxiety and stress but it would be advisable to get a complete examination and investigations as ECG,Blood test etc to rule out the exact cause.
Some simple measures that can help you include-
1. Practice relaxation exercises like yoga, deep breathing exercises, etc.
2.Do a regular workout or exercise like aerobics.
3. Decrease sugar intake in your diet.
4. Indulge in some interesting hobbies.
5.Listen to music , go to parks or picnics with friends, etc.
These will relax your tension to a large extent and you will feel better.
Take care!