I have no experience with this method nor do I have any with hard drugs, but have done a fair share of reading. I also don't know how much you weigh, your previous drug experience or your tolerance so I will have to guess your outcome.
Here are some pros and cons, based on my limited knowledge:
The pros. I would presume is that your "exit" would be incredibly peaceful. I've heard that strong opiates like heroin offer an incredibly pleasant high. It's so strong, they get angry when they die and have been brought back with Narcan by paramedics.
The cons. If you fail, you will most likely suffer through a lifelong addiction so insidious that it destroys everything in your life. As your cravings get stronger and stronger, and your entire life is spent scoring more and more heroin because your tolerance increases. Some addicts live for years, even decades but their quality of life goes to shit.
Whether you choose to CTB or not, I hope that you find the peace you seek.