Have headaches left temple, loss of appetite, occasional weakness on left side. i have been stressed and have a lot of anxiety. can tht be the cause?

Definitely: Stress & anxiety can cause lots of symptoms & left unchecked can lead to more serious illness. Make sure you are eating a balanced diet, drink water, excersize & take time to take care of yourself - read, relax, have fun, take a quick nap, get a massage. If this is an on-going problem see your md or a counselor to learn to control the stress or possibly get short-term relief with medication.