Hi ! On chapter 2 during the quest "Where is Triss Merigold?" , after getting Triss' bandana i was told to get back to Philippa and give her the bandana, when I get to her house , her helper says that she is out taking care of Saskia and that she would come back later. She never appears again and i can't do any other quests because of that. I also attemped to go to where Saskia is but the two guards don't let me get inside the house.

If I remember correct you need to complete "Subterranean Life" (or maybe another quest related to Saskia cure) quest before Philippa return to her house.

I have already finished that one , the next one that I have it's the "Royal Blood" quest, but Stannis refuses to give me some of his blood .

I think you need to finish this one so Philippa will return to her house.

I can't finish it because it says that i must wait until the history continues.

You need to talk to the groups of people hanging around Stannis's room.
The peasants , dwarves & Iorveth to find out who poisoned Saskia & how.
Once you have dealt with Stannis, one way or the other, Phillipa will be back home.

Ok I might sound frustating , but there isn't anyone outside of Stanni's room.

I think i'm going to try to redo the entire chapter with the order that appears on the walkthrough. Thanks for your help Ritualisto ! :)

(Update): It's seems that my game had a glith during the quest "Subterranean Life" that made the dwarfs that came along with you still folling you even if you had already finish it.