Failed upgrade 2.6 to 2.71

I just tried to upgrade my blog. I followed the steps very carefully and when i was at the upgrade.php phase. I had to manually go to enter the upgrade php at http://www.smellmyblog.com/wp-admin/upgrade.php…there was a line of error code at the top of the screen but it still let me click the upgrade database button. Now at that link it says database is up to date.

when I try to login at http://www.smellmyblog.com/wp-admin I get the following errors

Warning: fopen(/homepages/4/d119650489/htdocs/smellmyblog/wp-content/cache/wp_cache_mutex.lock) [function.fopen]: failed to open stream: No such file or directory in /homepages/4/d119650489/htdocs/smellmyblog/wp-content/plugins/wp-cache/wp-cache-phase2.php on line 96

Warning: Cannot modify header information – headers already sent by (output started at /homepages/4/d119650489/htdocs/smellmyblog/wp-content/plugins/wp-cache/wp-cache-phase2.php:96) in /homepages/4/d119650489/htdocs/smellmyblog/wp-includes/pluggable.php on line 850

I am not sure what to do. I went into my config.php and it seems fine to me. there are no characters before or after the <>.
also both of the files mentioned DO exist on my server.

please help