Sometimes you do not require a major reason for our problems. Many a times,  we struggle to handle small issues and misunderstandings only. There could be various other reasons too.

hi I can understand your situation, some times anger is inculcated either due to situation or its because of suppression sadness feeling is grown to anger. I think you also lack confidence in handling any issues either it is related to self or others. In which you are feeling of low self esteem and insecure in different things. with half signs of emotional disturbance don't consider yourself as depression. there are lot to be analysed. Approaching here itself sounds you are started keeping a positive step, it means you are introspecting(identify) your problem and wants to solve in a better manner. take care stay positive