Hello,
Welcome to Health Care Magic.
I understand your concern.
I will explain you why are you having such problems and then I will discuss about therapeutic issues.
As you have explained you have a very traumatic experience of childhood in the form of danger to life by your own brother. Apart from this you have perceived so much other stressors in your life.
In your case you are genetically vulnerable for psychiatric illness because of family h/o serious behavioural problem in your brother (? psychiatric illness). Secondly traumatic childhood experience had definitely an adverse effect on development of your personality and it has caused constant sense of insecurity, poor trust in others, persistent worries about safety and repetitive memories of traumatic childhood experience causing difficulty in thinking positive about future.
Apparently because of depressive illness you have developed distorted thinking like sense of failure, helplessness, hopelessness, bleak view of future and afterlife, distorting neutral events/actions of others as intended to harm you, and thinking yourself victim of all the misfortunes happening.
All these factors have adversely affected your life significantly and brought a constant unhappy state, a feeling of being harassed, irritability on minor issues, poor frustration tolerance and repetitive intrusive memories of your bitter past.
So, definitely you need a help. You must consult a psychiatrist who may advise you some psychotropic medicines to get rid of your psychiatric symptoms, “psychoanalytic psychotherapy” to make you understand your problem and personality, ”coping skills training” to help you in dealing with your problems in a better and effective way and "cognitive behaviour therapy" to correct your distorted thinking.
I wish you all the best.