Screen freeze during game recording.

I can't record my gameplay and play at the same time because the game freezes every half second and sometimes gets stuck for 2 seconds. It's impossible to play like that. But if I only record my voice, it doesn't freeze at all, but the game and the recording will only have my voice. I've tried everything. Is there anything I can do to solve this? Like recording the operating system sound without freezing the game?