Piles treatment. Anal fistula or piles?.

Three months ago I started feeling pain while defecation...The area around the anus swelled...After doing some Google search I found that it was hemmerroids...So I first took some remedies like increasing fibre rich content in my food,sits bath thrice a day,drinking plenty of water etc...Slowly the pain reduced and swelling also lessened...Then I went to a general physician who recommended pilex tablets and smuth cream for 2 weeks(without physical examination)...All things became normal,pain almost went away,swellings gone except one on the left side opening of anus...It sometimes shrinks sometimes swells...It feels like a skin...It sometimes causes itching and sometimes causes burning sensation while defecation...It becomes a bit painful sometimes after riding a bicycle or any other vehicle or even when touched by finger...Soo what to do? Is it a blood clot which needs injection or is it anal fistula or piles?...