hopeless romantic society discussion

Ok I’m back. So my problem is i have a character b who deeply loves another character a and views them as their savior however character a kills character b’s not only best friend but found family member I’m currently struggling on how character b should feel yes they feel hurt, betrayed and all that other stuff but they also love character a so very much this person was their one beam of light was their only light in the darkness. So how should character b feel? (This is mainly to see peoples opinions and broaden my insight)