Thanks for your query.
Since your foot has become red that means you have probably developed a severe infection.
As the wound is deep and infected you need to immediately visit a ER or a hospital and may need to get intravenous antibiotics as oral antibiotics
were not effective.
Also there they will clean the wound and do the dressing.
As you have got severe infection any treatment and cleaning may not help and you may need a proper medical care with sterile dressing.
Hope this is helpful.