If you are easily pressured and you trust people before you really know them, you do not belong in the field of international relations unless you first study diplomacy. Diplomacy is the art of knowing who to trust and when.
You are an idealist and must become more realistic. You have probably been raised by good honest people who maybe did not teach you how to assert yourself against fast talkers and untrustworthy people. But you are young and you can learn this.
Stone is ruby or red garnet for mental strength. Wear it on your chest or on the right hand, and wear gold, not silver. Cut short or put up your hair and wear sturdy dark leather shoes, not sandals or cloth shoes.