Hi u/Top-Principle-8610 - with a $2,000 budget, the best value for your money would probably be a used Panasonic S5II with the 20-60mm kit zoom for $2,019.01 from Amazon Warehouse Deals. [Referral]

You'll feel very comfortable coming from the GH5 because of the S5II's similar menus and physical layout, but you'll also have much better autofocus and low light performance.

Hope this is helpful and good luck with your upgrade!