Dude this same thing happemed to me today. It went into safe mode for no reason and it just kept rebooting over and over..it only stopped when i went into the bootlader screen(what ur at right now)
The way i fixed my phone u might not like it...but its better than having no phone.
I went into recovery, then wiped all data and did a complete factory reset. It worked for me..not sure if its going to work for u.
At the rime it was doing this, i had unrevoked 3 root with clockwork recovery mod.
If what i said dont work, post more details on ur current config....
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