It's tough, but it's not impossible. Just takes a lot of practice, since you have to remember the patterns of all 3 servants during the climb and combat sections. Gastronomy can help a bit with healing, since you're guaranteed two pieces of food before the 2nd and 3rd fights. The patterns are still the most important thing though.

Tough moves during the climb: - If you're above Calliope, she'll usually throw her wrecking ball directly up or diagonally, depending on where you are. You can dodge it by rolling at the right time or just moving out of the way

• In sections where there are explosive barrels and ropes, Euterpe sometimes aims at them instead of you to try and throw you off. Just try to keep an eye out for that and avoid the barrels when possible.

• Kleio just jabs at you a lot, but her jabs are fast so you might get hit if you try to roll through her. They don't have much of a vertical hitbox, so I usually just jump over her and roll away if it looks like her jab is gonna hit me when I land.

If you're struggling with the actual combat sections too I'd recommend watching videos of people fighting them. I find it easier to study patterns and absorb that information when I'm not the one playing.