Have you had success with encrypting TURN servers? In trying to host my own Matrix server and have E2E encryption for texts, video, and voice, I found that video/voice had to be disabled as Let's Encrypt and SSL weren't compatible.
Setting up STUN and TURN is a real pain, though, if you run into any issues.
Actually, I'd suggest reading the entire document when you have time. For now, though, at least have a read of that section (it's short and sweet).
[0]: http://www.catb.org/~esr/faqs/smart-questions.html#beprecise
You won't be the first (nor the last, though if I can have the chance to improve that at some point I would love to) person to have struggled with it.