Login failure

Thanks Lee….tried that and emergency PHP method of getting
http://codex.wordpress.org/Resetting_Your_Password

Nothing was working but then upgrade WP from 3.9 to 4.0 and voila
the Emergency PHP script work and was able to get into WP.

But then about a week later, the same thing happened, and I was closed out again WP site . So wondering if I uninstall back to 3.9 and then install back to 4.0. will I loose all my work.

I have backed up WP on my server. Is there anything else I should do safeguard things?

Adding insult to injury Google has placed kayakkauai.com as a “hacked site”.
if you do a Google search of our company.

Any sage advice appreciated….out there. Micco