If you let Photoshop idle for a few minutes does this get better? Does the RAM usage keep going up even if you're not actively doing anything in PS?
Here's a few troubleshooting steps to try first:
1. Close the Libraries panel, quit and re-launch the application 2. Turn off font previews: Type > Font Preview Size... > None 3. Turn off the Welcome screen: Help > Welcome... - then from the Welcome screen, choose the New Features tab, scroll to the bottom, and click the do not show again checkbox. Close the Hello window and quit and re-launch.
Please let me know if any of these changes help. If not, we can try some other troubleshooting steps.