Unless you can 100% guarantee that there are no security flaws whatsoever in your Infra, I wouldn’t do this.

Why is your App cryptography-heavy if it’s a messanger? Don’t you just have to call msg.encrypt() or similar and then the library handles the rest?

Hi, very cool to see you learning and having fun! Keep at it!

You don’t choose FOSS because you like abstractions and general solutions but because, well, it is free. And you remain independent. And you can actually verify yourself that the software is well-built and worthwhile to build on.