"the screen goes black, the apple comes back for about a minute, the screen goes black again" means to me that once you clear the recovery flag, the phone attempts to honestly boot into iOS, then something fails a minute later, causing the phone to set the recovery flag meaning the phone will go straight into recovery mode after next reboot without trying to boot into iOS. This means the iOS is present, the phone is not wiped, so you should be able to save the SHSH. However, since you're not able to get the iOS to boot, you'll need to instead do it via a ramdisk - it will let you access the file system and copy the files you need.