Welcome LondonGirl87. Deciding to disclose your diagnosis is a very personal decision. I have made the choice to be open about my diagnosis in my personal and professional life, but it's something that once you have done it you can't take it back. This is not to say that you shouldn't disclose I just think it's something a person should think about.
We all do need support and I don't think it's necessary for you to disclose your diagnosis to reach out for help. A simple I'm not doing well and could use a friend is enough. It could be as simple as just asking to go for a walk, to a movie or for a coffee.
I hope you find this site supportive.