but...I've had my iPhone 5 with iOS6 for over a year now...you mean for all this time this risk has been present and just being patched now in iOS7? I'm confused about that part. I don't use SSL websites on my phone
Even if you don't visit SSL websites, you are still likely using SSL connections often, e.g. in Mail, iCloud, iMessage, software updates and many other apps that rely on SSL to protect passwords and other sensitive information in transit.
and don't use free wifi, I'm mostly on LTE all the time except home wifi, never had a problem all this time.
Now that this bug is out in the open and tools to exploit it are widely available, many "bad guys" will try to get in on the action. While the risk is highest when using public Wifi hotspots, there are also ways to mount man-in-the-middle attacks deeper in the network.
This bug is so serious because it undermines THE main end-to-end encryption mechanism used for secure web transactions today. You should not underestimate this. I strongly recommend to apply the patch, even if you are not a fan of iOS 7. It is just too risky in my opinion.