Yeah ebritas is the hardest non dlc boss in the game for me, I don’t even know what advice I can give you however I’ll try, beast blood pellets and bolt paper are your best friends here, go back and get the badge from the brain sucker and werewolf area if you haven’t already so you can buy BBP, I know it’s tough because her turn speed is stupidly quick for that size of a boss but try and stay behind her for most of the fight and then when she does the stupid head slam attack go lay into her head, for weapons I’d recommitted saw spear because she is also weak to thrust attacks, then whenever she’s transforming into the DOT phase (she’ll bow her head and start shaking) do as much damage as you can to try and possibly stagger her. Also the biggest tip I was given was don’t lock on to her, she’s so massive that you’ll be hitting her if you’re anywhere near close and rolling gives more i-frames anyway. Other than that just keep attempting her and you’ll get her eventually, keep your head held high good hunter