I personally think these voices are from neurochemical imbalance or from a brain programme that is running e.g. trauma. It's not your voice saying this, it's that your brain is unhappy chemically speaking. This is from my experience of these voices.
My voice for many years every day was 'I hate myself and want to die'. That was my morning voice. It used to be just the mornings, though the whole day was full of agitation etc. The hate voice I was lucky went with ayahuasca, though my depression stayed with me and worsened as I got older.
The wanting to die right now isnt' with me as I have a treatment that is helping. It's been about 3 weeks. Over the past few years, I have had maybe 3 or 4 weeks off a year, due each time to some supplement that helped.
I'm sure or hope you have tried treatment, and I know how hard it is to find something that helps. All of my own personal research I have put in this forum. Different things can help different people. It's worth trying different things.
I'm just saying the voices are not you and that you can keep trying to treat them.