Overthinking

Soo my dad is supposed to be schizophrenic nd i might have it nd ever since i was in the 7th grade ive been cutting on nd off nd i would have depressive moods somedays next day ill be fine nd happy nd when i start thinking i over think stuff nd sometimes it makes me cry so my first love told me i should stop doing it or fix it cs its kinda annoying nd a turn off.. where do i start ?