Installed MSM, wasn't working; now can't login to EE control panel.

Hello. I just installed the MSM on an EE site (current version of both). I did the installation of the MSM as per this page: http://ellislab.com/expressionengine/user-guide/cp/sites/install.html

Then I went to this page and followed the steps for creating a new site: http://ellislab.com/expressionengine/user-guide/cp/sites/createsite.html

I created a new site (site2, let’s call it) and got as far as step 2 on the ‘create a site’ page I refer to above: I selected the import options. I then had 2 sites. Next I wanted to go to step 3 on the ‘create a site’ page (where you configure the site in admin > general configuration, etc), but when I use the ‘sites’ menu at upper right and select my site2 from there, it brings me back to site 1. I can’t access site2 at all.

I thought I’d log out and start again, and now I can’t log into my EE control panel at all. When I do, the form acts like it got a submission but then brings me back to the login screen again, with the fields blank. I can’t get past this.

I had not gone onto the next steps in site creation, where you set up domains/sub-domains.

I will say that the only other thing I did was point my new domain name at the hosts servers using the hosts nameserver info. The front end of my original site works. But the EE control panel is inaccessible. I tried logging in using a different browser in case there was some sort of caching problem; doesn’t work there either.

Help!