It is difficult to put an exact time at how often the Google bot visits your website but you should give it a few days. If still nothing then please make sure that you have the keyword meta tag in your homepage and only have 'millenniumweddings.com.au' in it.If the website is now back online then things will return to normal.Another word of advice is to regularly add new content such as a blog and have customer's link back to your website from their own website or blog. Finally, make sure that your homepage has words which are in context with your business. This does seem to be the case already if you were previously on a high result.You can also manually submit your website to the search engines by reading this click me
Hello again 404 is when the page is not reachable. When your page gets fully indexed things should return to normal. Please give it a few days for the Googlebot to crawl your page again. If by Wednesday things still aren't right then you can follow my suggestions above or do some SEO. However if SEO was an issue you wouldn't have reached the number 1 results page before.Let me know how things go. Is this a Wordpress website that you maintain yourself please?