I wonder why he is attacking me? I never attacked him during the quest when I'm going to talk to him... What should I do?

Found this: Florentius may attack you for no reason at all. No known fix. Not even reloading or sheathing will stop him. (If you have a bounty I would suggest paying it before doing the quest or pay and return after a strategic retreat. Alternatively PC users can apply a simple console command workaround player.paycrimegold &--#60;amount&--#62; &--#60;factionID&--#62;).

I can't kill him but when he is as low as he can get in life he curl up and some seconds later he rise up and starts attacking me again, but exactly when he start to rise up I can see the text: Press E to talk to Florentius Baenius. But he doesn't start talk to me and attacks me.