A login problem with a custom theme (widgets and jetpack issues)

Hello all,

For a couple of days, I haven’t been able to log in my blog as administrator (or any other user) and I would like you to help me solve this riddle.

Preliminary information

Here you have my blog’s adress: http://www.escueladiplomatica.com/

I programmed the blog’s theme almost from scratch a year ago or something like that. It has been working “fine” (let’s avoid talking about tweaks and hacks and other junggling) for all this time, but a couple of weeks ago I updated to the last wordpress version (3.8.1) and installed jetpack.
When trying to connect to wp.com with jetpack I got error 37200, but finally it was possible to connect by deactivating the custom theme, connecting from twenty-fourteen, and then reactivating the custom theme. Nonetheless, most of the jetpack widgets were not working properly. I activated “links”, “fb widget” and “suscription widget”. After that, I widgetized the default sidebar and used the dynamic_sidebar() function to show the stuff. Although I connected the blog to wp.com, most of the jetpack widgets cannot connect.
So, I was playing with these new widgets, formatting them and these things until I tried the “suscription widget” by suscribing myself (:D). Then the wp-admin login page gave up working. It starts connecting but it never finishes. However, the admin panel is working because I could connect from another computer in which the cookie works automatically and post something. As well, the blog is functioning other than the login page.

Looking for solutions

Before writting this post here, I tried some solutions. I searched the org and found this link:

http://codex.wordpress.org/Login_Trouble

Here I post some information about the link’s suggestions:

Wait until it fixes magically after 2 or 3 days -> It didn’t work.

Reset the admin’s password -> It didn’t work.

WordPress multisite network -> DOMAIN_CURRENT_SITE value does not exist in wp-config.php file (version issue?).

Enable cookies method -> It didn’t work.

Disable widgets method -> It didn’t work.

Deactivate theme method -> It didn’t work (once it is deactivated the blog dissapears completely!!!). Disabling widgets and deactivating theme (both) didn’t work.

New login file method -> It didn’t work.

Headers already sent method -> Nothing.

for the time being, I can’t access and check the database, but I will contact the admin, check it and let you know.

Any suggestion?

Thank you very much!