I'm not here to tell you what you should or should not do -that is something only you can decide.
But what I will say is that if you are planning to die tonight but are terrified of it, maybe it doesn't have to be tonight? I don't know your circumstances whether there is a reason why it has to be tonight or something else but, it is normal to be afraid to die.
I can't tell you how many times one moment I'm so confident and sure that I want to die and am willing to do whatever it takes for it, but the next moment I'm questioning everything. Please correct me if I'm wrong but could it be that you yourself may not want to die but the situation you are in is kind of nudging you to do so? I don't want to assume so if I am completely wrong please let me know.
If you are panicking and nervous right now maybe it isn't the best time to CTB since that gives more room for error. Which could increase the chance of something messing up and you ending up in a hospital instead of dead.
Again, I don't know your situation so I could be completely wrong. But if you are scared, maybe give yourself a chance to stop and think about everything before going through with it to make sure this is truly want you want right now. Maybe even, everything you are feeling right now will pass and you will live another day.
Either way I fully support your decision and if you need to talk about anything please feel free to dm me