I feel like a threat?

I've done something really very stupid at work. And now I feel awful and crap about it. I have been off sick for the past 7 months because of it. It was my first episode. I feel like a threat to this person. And that they need to be protected from me. I didn't do anything to hurt anyone but I kept writing to a colleague and it spiraled out of control. I couldn't stop writing and I don't remember the things I said. Some of which were probably awful things.:( I asked this question on another site and everyone said it's my fault and I am a threat to this colleague. that I should leave. And I shouldn't blame them if they don't want me back.I can't bear to face these people again. I am so ashamed, so embarrased and so, so sorry for the trouble I have caused. What should I do? Occupational health reccomended a transfer but it's a risk because if I don't get the transfer I lose my current post as well.