I have a problem with the SEO on my website. I have set everything up - I've really spent quite a lot of time tweaking my website's SEO. I then fetched the new site using the Search Console, after just a couple of hours (the next day respectively) the results were great, I've seen my page on the upper half of the first page when searching for this query
[stuff_I_sell_(keyword)] + [city_name_of_my_bussiness].
I actually tried many combinations of key phrases my potential customers might looked for, and it worked great. My site was there, with up-to-date titles and descriptions.
However, after a day or two, it is completely gone. Basically I cannot see my site on any page of the Google's results. I am unable to find my site, unless I write my company name specifically.
This had happened to me before as well. What might the problem be?