Hi jandb130,
It sounds like you're having an issue with lagging when trying to stream from your Mac using OBS. We're happy to assist. From the information on the OBS system requirements page, we're seeing macOS 10.12 or newer. You can view additional requirements here: Open Broadcaster Software - System Requirements
Additionally, there are some helpful tips in the section "OBS is dropping frames. How can I fix this?" found here: Open Broadcaster Software - FAQ
If this is a MacBook or iMac introduced in late 2009 or later you may be able to upgrade the macOS. You can find details here: How to upgrade to macOS Sierra
We hope the information helps.
Best!