You only need the suture needle in your inventory to stitch deep wounds, which is consumed upon use. You don't need any other skills. If you can't 'stitch' your wound, it's probably not a deep wound or you didn't remove the lodged object yet.
Another possibility is that you might need thread in your inventory as well. But, I never had any thread on me. I stitched my wounds with only a suture needle.
bro i need help with laceration badly, i keep putting on stearilized bandage but it dont work. i dont think you can stitch it either, and its also on the neck so help if u can
Eat a lot of food to help healing. Then try disinfecting the laceration and use a regular bandage. Change and clean when its dirty and keep eating food. Hope this helps. And good luck!😅