How do I heal a broken relationship I Caused?

[DokkenFan1984D]

My Fiancee and I have been together for 8 years now. Some childish drama happened on my part. An know I've caused her pain to the point where she say's she'll never trust me and that I've lost everything. I REALLY do love her but am an idiot for doing something so childish to our relationship. How can i try and make steps to let her know i messed up royally and that I'm TRULY sorry from the bootom of my heart.

p.s. thought about committing suicide