help with gta

Is it constantly 5? You should check if the settings are appropriate for the computer's level. And check to se if you have a mod config making it limit to 5.
Sometimes OpenLimitAdjuster's config is bad and it caps FPS.

Set the frame limiter in your settings to on and try /fpslimit

What are the full specs of your pc?

Try reinstalling. It worked for me when my fps was locked at 90.