Constant headache from 3 months.

These are features of obsessive thinking, which in psychological terms is described as unwanted urges or impulses or ideas or images that come to mind without our wish. They are due to many reasosns but one can find incidents of abuse in childhood either physically or emotionally, feelings of rejection,  too many moral obligations on oneself, and lot of suppressed anger. This anger may be due to similar suppressed expressions at home where one or the other family members (mainly parents) are not able to vent-out their anger properly. You would have learnt these patterns of thinking and behaviors from home and currently facing problems like the ones mentioned by you. Feelings of harm to self or to other closed ones is a sign that you feel uncounscious anger against them which is irresistible and unwanted because it goes against your moral beliefs. Thats why its creating worries for you. Your attachments with family members or loved ones are deep enough and superficially you are expressing affection with them due to some problems at home. You need to assess these issues that are present in your family since childhood and are effecting you. Only a clinical psychologist can help you in this.

Visit a clinical psychologist.