I've experienced same problem. It's begun yesterday, before everything was ok. After that i reinstalled OBS completely (cleaned registry, deleted user settings). My internet connection is fine while streaming and in moment of reconnect. Used different servers on Twitch and other streaming services (e.g. CyberGame.TV). And always same exact problem - 10 minutes, reconnect, 10 minutes etc...
Installed and launched as administrator.
Here is two logs from two diffrent streams to Twitch and CyberGame.