I'm about to share secrets with my boyfriend

Advice please ... I told him that I will come over tomorrow and tell him everything that's been bothering me. 
Just recently I suddenly got super sad by the smallest thing. Ever since I've been crying , even started cutting . I can say that it's happened in my recent years . But I've been having problems with college , friends, even my boyfriend, job, body issues . My relationship with God... also I like to imagine myself dying ( I would never in a million years commit suicide ) but I just like the images that I make in my head and sometimes they are. Bad deaths. My throats gets tight and I. Break down into tears .. I've been cutting and I'm very insecure . I have never told anyone my problems but my boyfriend of almost 9mo  is worried , so tomorrow I think I might tell him everything . But I don't want him to judge me or to think I'm some silly teenage with silly problems . And I know they are way more bigger and important problems than mine but I feel like all of this is weighting me down and I don't know how to handle ... I don't feel myself and I don't know why this happens . Advice please!!