[Q] GT-N7000 (rooted) constantly restarts after Jelly Bean upgrade. Help!

Hi all,

So, a little earlier today, i noticed the 'update available' appear on my phone here in the UK. Although I rooted my phone when it had Gingerbread, the update to ICS was fine, so I decided to go ahead and accept the software update to Jelly Bean.

Big mistake!

Now when I turn on my phone it is really sluggish, but after between 10 to 40 seconds it restarts itself.
It does this constantly so it is now impossible to use my Note.

I really need to get it back into a working state, ideally without losing my photos.

What would be the best solution?

If I can back up my photos to my PC then it won't matter if they get wiped from the phone. I'll try that as soon as it is charged up.

Another thing that may cause an issue is I can't remember which program I used to root the phone. I remember it was just a straight forward root, with no custom ROM installed, no clockwork mod thingy and no binary counter update.

Should I just try to unroot the phone to see if that fixes it?

Since I can't remember what software I used to root it, does that mean I can't unroot it?

Anyway, hope someone can help.

Cheers