Itching arround anus. Go through it.

Hi doctors I m facing this problem of itching arround anus. And sweating also for last 15-20 days. When I pass stool. It feel like some skin is cracked and feel burning sensation and when I touch the part looks hard little swelling. But no pain only desire for extensive itching. And swelling go away after 5-10 minutes passing stool . And also have farting issue with that more in after 7-8 pm . I don't know is it related to this or not. I am a teacher runs coaching so arround 8-10 hour sitting jobs. So when I change dress. It feels sweating . So I am worried about it. Need medicinal advise on that . Whether is it fissure or piles or anything else I have attached image please go through it. Thank you sirs/mams