my wp-admin is not accessible anymore on 2 domains

Hi my wp-admin is not accessible anymore on 2 domains on the same server and I think my host is starting to give me the run around like I have seen in a lot of support tickets on the Net from admins having the same issue (basically they are blaming WP or Plugins that magically rewrite my site all of a sudden).

My site is fine but as soon as I log into my wp-admin (or wp-login) it redirects me to the same page it is supposed to redirect regular users after they log in (activity stream) and when I try to get back into wp-admin I am getting no response and run into a 504 time out plus occasionally see 500s too.

When I then try to browse the site it isn't possible, I am getting 504s, 500s and 405s but it works agaij after 10-15 mins and I can do minor admin tasks like editing groups on site (not in WP-admin)...

It is a BP,MU site (the poker one that is tied to my account if you are from WPMUDEV support and reading this)

Not sure what to do and I urgently need to edit some things in the admin panel :slight_frown:

Thank you!
Toni