Oh, I hope it all goes well! I do think the discomfort goes away over time. I can't speak for invisalign specifically, so I might be wrong about that, but I had braces for two years as a teen and then wore a retainer for a few years after that, and the initial procedure of getting them on and then the follow up adjustments were always the worst part. After I got used to the feeling of them in my mouth it stopped feeling so sore.

Also, happy birthday!!