Peri anal hematoma is not common without trauma, if you have external piles, this can be thrombosed piles..it can get necrosed (black with infection) if not treated properly. I would advise you to Consult a Surgeon. Meanwhile for the time being you can use the following tubes.
Next Steps
lidocaine jelly for local application, hot sitz bath (google how to do)
Health Tips
consult surgeon