I think I know what you are talking about.
keep writing here on the forum and talk to the Samaritans or any other help line ---just keep talking. Gather your energy to see your g.p. and/ or a nurse at your local surgery, just as a safety measure. Let them know how desperate you are feeling and they will make your appointments a priority.
The sort of plan above can get you through the days when you are feeling really desperate.
On the Livinglifetothefull web site, there is a 'panic' button and a page with a list o things to do when you are feeling that you can not go on.
you may have to register - but the information is simple, straightfoward and helpful.
Please check out the page.
the site is run by Psychiatrists and trained professionals.
Don't give up,