A funny piece of advice, I have an actually very good friend (we still are, but at a point in history our relations became a bit dark) who knew that I was going into therapy. I didn't actually accept the fact that I had to go well, and I felt ashamed and weak when we talked about it. Little did he knew, in the meantime I got much better, accepted the fact and started freely speaking about it with other people here and there. Not when not asked, but when the topic of mental health came along, I wasn't shy to expose the fact and encourage people to seek their own. And in one relatively big dispute (minor from this distance), he kind of tried exposing it against me in front of some mutual friends who actually already knew (I told them in the meantime). Well, he looked like massive jackass.
In conclusion, don't be ashamed for seeking therapy. Yes, it may feel shameful now, which is completely unwarranted, but a part of the process of healing is also dealing with the existence of the issue itself and taking a different stance at mental health issues.
As for the blackmailers... just rot in hell.