Why don't i stutter when I'm speaking to myself or whispering something but stutter when i talk to someone?

Why don't i stutter when I'm speaking to myself or whispering something but stutter when i talk to someone? I stutter sometimes a lot , I thought it was because of my anxiety and nervousness but even i stutter infront of my own family members. It's so distressing that sometimes I can't even speak what i want to say or stand for myself. This stutter started when i entered college but i think i stuttered at a young age but i didn't paid much attention to it and the stutter was non existent. But after getting into college I become very self conscious of my stutter that sometimes I can't even say my name properly.I feel so hopeless and depressed that i feel like ending it all. I also practiced so many methods like speaking solely breathing before speaking but none of it works for me to get rid of my stutter. But i can speak properly without a stutter to animals and alone. I don't think it's nervousness or anxiety.