I have very high levels of stress in my job and personal life. how do i know when i am not coping and what can i do?

In general:: Stress and the amount someone can take is highly variable. If you are sleeping ok maintaining a healthy weight (ie not losing or gaining ++) not suffering from anxiety or low mood then at a guess you are likely coping. If these things are off then suggests there is an issue. Probably start with doctor appointment if so to check - stress vs anxiety vs depression vs medical illness and treatment