[jamesk_au]

The problem, in your own words, is your present psychological state.

Irrespective of whether you give the speech, you should see a psychologist or a psychiatrist as soon as possible. There is no substitute for having an experienced, rational, objective and trusted person working with you to resolve your concerns.

The thought of confiding in an expert like that may be a source of discomfort for you. It is reasonable and natural for you to want to try to resolve your concerns on your own. But you say that you were unable to leave your house for a period of some five months. On any rational view, the time for self-help remedies is long past. You need to have this resolved if you are to get on with your life. Don't question it: just do it.

If you do it soon, you may find that you are in the same position that many other first-time public speakers have found themselves in, with the result that there are plenty of well-worn strategies available to you to tackle the speech you've been asked to give.

But you need to divide and conquer: solve the other problem first.