Can't talk to my best friend

Hello,
This is my first post on this website and I'm writing this as soon as I registered because I don't know what to do anymore and I'm seriously so desperate now. I'll warn you that this is a pretty long story but I would really appreciate any kind of help because I keep crying out of frustration. So if anyone spends their time on reading this then thank you so much.

I met my best friend in an online game called Overwatch. Just totally randomly, it put us into the same match. It was a little over two years ago. We played together a lot, talked to each other a lot in chat so we got to know each other well pretty quickly. Neither of us are native english speakers but we aren't from the same country either so we communicate in english. We became really close friends over the first year and in April this year, we just kind of "officially" became best friends. We live really far away from each other so we have not met each other and probably still won't meet at least until next year or two.

Now, my problem is that it might never even happen because I feel like I'm kind of ruining this friendship by being way too shy to talk over a microphone when we're playing videogames together. This may not seem like a big problem but trust me that it is. We play together almost every day for 2 or 3 hours and I feel so terrible when I just can't bring myself to talk. So the only form of communication we have because of me and my annoying shyness is just over messages.

The thing is, she has helped me with my mental health so much and she genuinely makes me a better and happier person and I've never cared about someone as much as I do about her. She means the world to me. But I just can't bring myself to open my mouth. I have no problems whatsoever in talking through Messenger or typing in chat while playing with her. I don't even mind sending her photos where I can be seen. (Yes, I am still shy about it and very self-conscious about my looks but I've sent her a few photos and now I don't feel that shy about my face.) But talking out loud to her is just the one thing I can't do. I just feel like my pronunciation would be bad, my accent would be annoying, I would talk too much or too little, I would just make annoying sounds or laugh too loudly and many other things.

I've had the microphone since July and now it's November and I've said about 10 words to her in total in these 4 months. I thought that after the first time I speak, all the insecurities and anxiety will go away and I'll feel comfortable but it didn't happen. I only started shaking and sweating and couldn't stop for the next 30 minutes or so. She uses her mic sometimes to talk to me and I told her about me being really anxious and she said that it's fine and she can just talk alone for now for me to get more comfortable and get used to her voice which I did but it only made me feel worse because now she's talking to me while I'm just responding with typing in chat. And trust me, I would absolutely LOVE talking to her normally with my voice. I would love to hear her laugh more and to overall just hear her pretty voice more.

So please, if any of you have any advice, tell me. I'm so desperate now, I've been trying for so long, I've been thinking about it every single week. It seriously just makes me sad and angry at myself. I'm considering asking my psychologist about any advice but I'm seeing her in a month and that's a very long time so please, once again, if anyone has any idea and read it all the way until here then first of all, thank you so much for reading this and I'm sorry for taking your time and second of all, I beg you, please give me any sort of advice. Even giving me your thoughts about this situation would for sure help a lot.

Thank you very much.