sorry this took so long to answer, i was raiding in WoW and i wanted to be able to devote a lot of thought to this.
while it may be stressful for them (as it is with my mom and my pronouns) the conversation isn’t about them. I can understand someone with a personal or mental health issue dead-naming and then correcting themselves perhaps (as long as it doesn’t put the focus of the conversation on them) because i know its hard. I still sometimes misgender myself lol.
If it hurts you, the best thing i can think of to do is to explain that to your friend. This about you and what you need. Explain to them how much this hurts you. Explain that even if they use it, apologise, and use the right one without a fuss, that’s even preferable to just ignoring your wishes.
Alternatively (and this is just a silly suggestion don’t take it seriously) you could always wear a “Hello: my name is ______” sticker lol