Where my wisdom tooth should be, it feels like my gum is coming away from the tooth. It doesn't hurt but I'm worried.

Do something. Call your Dentist. Have a Pro examine you and see if treatment is indicated. That' same lot better than worrying.
I am confused,but. Gum tissue should not be coming away from the tooth. This suggests the presence of periodontal disease, a gram negative anaerobic rod bacterial infection. See a dentist.
Overlying flap. Probably an overlying flap on a partially impacted wisdom tooth. See a board certified oral & maxillofacial surgeon for evaluation/recommendations.