I had 4 hernia surgeries bout 3 weeks ago. One incision is extremely red, painful, raised up, and pussy. Could somethin have torn open inside again?

Wound Infection. What you are describing are classic findings consistent with a superficial wound infection. This requires follow-up with your surgeon for recommendations regarding local wound care. This may include antibiotics if the wound is associated with a hernia repair utilizing mesh.
Infection . Pain, redness and pus to a recent hernia repair site sounds like an infection. Call your surgeon immediately as this absolutely needs to be treated.