Clips with Different Frame Rates

I made a rookie mistake (as a novice): Recorded one of my clips (commentary) using 30 fps, while everything else was filmed at 60/59.94 fps.

I have the 30 fps commentary on a second track and showing as a box in the corner of my video. After rendering, the 30 fps commentary looks fine, but the 59.94 fps is choppy.

Project is currently set to 59.94 fps.

Is there a way to best combine the 2 frame rates into 1 video?