I am also Catholic. To confess is better not to confess. This is the one person that you can tell everything to, and he cannot tell a soul. The Catachesim of the Catholic Church does say that those that die by suicide, if they were suffering from a mental illness, are not automatically condemned, as it had in previous iterations for suicide. Here's the full text:
If suicide is committed with the intention of setting an example, especially to the young, it also takes on the gravity of scandal. Voluntary co-operation in suicide is contrary to the moral law. Grave psychological disturbances, anguish, or grave fear of hardship, suffering, or torture can diminish the responsibility of the one committing suicide.
Again, the confessional seal is absolute. Breaking it, even if he thinks it is saving your life does not matter in terms of consequences, which are clear: automatic excommunication. He might want to talk to you in the confessional, to try and change your mind. How you respond is your choice. In the end, if you've given a full confession, you're absolved.
I hope this helps.