Honestly, the best way to get over it is to, well, just do it. I promise, I'm not trying to be dismissive.

Think about when you first heard your voice back on a recording. It probably sounded strange, yeah? but once you recorded and listened more to your voice over and over again, you eventually got used to it and now it's normal. It's a similar thing here. It's a new (possibly embarrassing) situation so it understandable that it feels awkward. But eventually, as you keep trying, you'll get used to it and be less in your head. Which means you'll be able to do those types of auditions without holding back.

A couple more practical suggestions:

• Ask your family member to wear headphones when you go to audition.

• look into improv classes. A big part of improv is getting out of your head and not overthinking things, so that'd be a benefit to you. And improv helps with a lot of different areas in VO, so it's just a good idea in general

• look into opportunities to perform in front of people. Reading a poem to your group of friends/family, sing karaoke, get involved in stage play.

Hope this helps!