u/Pakeithpsy

Please, I am begging for help, all the search engines and YouTube can't help me at all and I cannot find a single alternative program that can do what I'm looking for.

I'm trying to gradually change the pitch of an audio file, with it starting out at normal pitch but then slowly shifting into a deep pitch as it goes on. I'm aware that the sliding stretch and time tracks do something similar to this but it sounds extremely unnatural and robotic. I want the audio to naturally deepen in pitch as it goes on without sounding like a machine dying. Are there any techniques or third-party plugins that can do something similar?