Judging from what you said, you'd better go to the hospital for examination at this time. If the incision is not deep, don't sew it up, just wrap it up, and then change the dressing on time, being careful not to get wet. If there is redness, you can take some anti-inflammatory drugs.

Guiding opinions:

Then eat lightly these days and don't eat irritating food. If the knife wound is deep, it's best to sew it up, so it will recover faster.