Root HELP, mobile stuck in Cyanogenmod Boot screen

My phone was working fine with Cyanogenmod Rom for a quite a while now. But I put someone else's memory card (after unmounting my sd card) and it started restarting. I tried to start the phone with my memory card, and even without any memory card at all, but the problem still persists.

Here are the details of my phone:
1. ClockWorkMod Recovery
2. CyanogenMOD 7.2 rc5.7
3. 8 GB memory card partitioned, with sd-ext partion of size 1GB, for using DarkTreamor A2sd script

I did suspect that there could be a little problem if I tried to open my phone with my friend's memory card (size 8 GB) because my memory card is partitioned but I was dumb enough to do it just because he kept insisting.
Now my phone keeps looping in the Cyanogenmod bootscreen endlessly.

I do have a Nandroid backup but it's 7 months old. I have over a 200 apps installed on my phone, and most of them were probably installed after my nandroid backup. I do have titanium backup of apps that is a month or two old.

So here are my questions:
1. Is there anyway to fix my phone back to how it was yesterday, without having to lose anydata?
2. If there is no way to do that, how do I do a nandroid backup? I mean since my sd card is partitioned and I have installed a lot of apps after my nandroid backup, are there extra steps to be followed or cautions to be taken?
3. If I were to start anew with a fresh custom rom, which one would be best or everyday use? I need a stable rom, if possible, which is okay with everyday heavy use. Which is the best ROM?
I have considered Cyanmobile X, CyanogenMod 7.2.0 RC1, EmanoN v7 and CyanogenMod 7.2 rc5.7 (my current rom), but if any other rom is better, that would be okay too. Which would be the best?

Please HELP!!!