Unable to connect after clearing cache

Hi. I've been struggling alot with high ping ONLY in bgs/raids/dungeons. so I decided to clear my settings/addons and such

So I deleted my Interface, Cache and WTF Folder. Now I can't connect.

I type in my username and password after launching wow.exe and it says "Connecting" for a few sec, then "Unable to connect" etc.

I've checked my realmlist and it's fine, and with a 0.6mbit connection i'm really not tempted to download another 17gb.
Can anyone relate or help me sligthly? This is driving me crazy

Thanks in advance

Well you did delete your interface, I think that's the key, however I'm not very good at these kind of things so that would be my two cents. Instead of actually deleting the interface you should have just manually deleted all your addons inside the folders inside it.
So try to remake your interface (depending on which expansion you may), for wotlk it's just basically Interface and Addons folders. If you deleted the whole thing and you can't recover it, you need to redownload some files that were pre-installed in the folders. That's my wild guess anyway. I would guess that if you have a friend who has the same client you could ask him to send you his files, that would be better than re-downloading it whole.