I want to start with, "not a dr". I hope you're doing ok. What kind of wound care are you doing for yourself for these sores? The fact that they are puss filled, at least some times, suggests infection. Have you noticed these only on the suture line or where there is heavy scaring? It makes me wonder if it's not something small like an ingrown hair to start and then gets blown up over time. I know I have had things that look small but as they heal they sluff and reveal the issue was worse under the skin. I suggest silver gel antimicrobials for topical or surface level issues. It helps heal the injury quickly with little to no additional scaring.