I also urge you to be very careful.

This is a psychological thing as much (if not more) as physical. A dom (both the "professional" ones AND the bottom feeders) will get inside your head. Use caution. Permanent damage can be done.

There are kink friendly therapists.

If you are on the fetish website that I am thinking of, it's full of predators.
Tread carefully. Talk to other subs. Go slowly. Read, read, read.
Another sub can guide you as a mentor and will perhaps put you in touch with a dom who is willing to be a guide online (you must still beware of mind games)

Take very much care.