The leaves are looking dry, and it appears to be growing inside a house. While Garcinias can be overwintered indoors in colder areas during the winter for a few months (as I do with mine every year), they do better when grown in places with more humidity than is usually found inside a house. That lack of humidity especially affects smaller Garcinia seedlings before they become well established. This is the time of year for it to be outside in the heat and humidity. Put it outside, in a shady location or in a sunny location under shade cloth. Very lightly fertilize it. Keep it watered but not waterlogged. It may not grow much more this year, but you will want it to be in peak condition before it has to endure a long Michigan winter indoors.