Recurrent lump near anus, blood and pus-filled. Is this something I have to live with?
From your history it appears that you are suffering from recurrent perianal sepsis. You need to get evaluated by a general surgeon / Anorectal surgeon.
The cause of recurrent sepsis needs to be found out by a thorough speculum examination supported by a MRI or CT of the region. This will help in determining the upper extent of the disease or communication. Only if the communication is identified and tackled will the problem resolve. Please do not worry and there is a perfect treatment for it with a competent surgeon.
Find a good anorectal surgeon in your area is the key.