There's nothing more awful than being betrayed this horribly by someone you entrusted your honest feelings with.
I hope that, however, your decision to CTB is not fueled by the actions of this person, but an honest desire to die. If by any chance, you want to CTB because of the unspeakably horrible things this person did, as difficult as it will be, I implore you to sit with your feelings and reconsider that possibly the most important decision of your life should not be defined by the inhumane actions of someone else.
Your life shouldn't have to be defined by the pain inflicted onto you by others, nor should your death be defined by the pain carved upon you by this person.
I truly wish you the best. Just know that whatever you decide to do, this forum will not admonish you for it. You are always welcome.