What should I do if my toes itch, fester and crack?

The toe seam is particularly itchy, and now it has rotted and suppurated. Judging from your description, it's probably foot pain. It is recommended to wash feet, dry them and apply "Dakening" ointment twice a day. Generally, it will heal in a week. After the symptoms disappear, continue to apply for a week, which can stabilize the therapeutic effect.