Blisters on Anus with itching, bleeding.

I am 25/m and have been sexually asaulted about 12 years back. After few days blisters started occuring over the anus with discharge and pain which subsided on there own after few days. With passing time and my fear of exposing it to my family members i came across with several another such episodes of sores and bleeding in anus and pain in lower abdomen. Constant negligence has now lead to the formation of skin tags around anus and a fistula formation. Also i feel pain in groin which radiates to whole left leg. Sometimes i feel stiffness and swelling with pain in palm of left hand, which i am fearing of neural involvment (i just pray it's not what i am thinking). Now overcoming my fear and social stigma, i want treatment of my problems. Any help?