Similar situation here and only recently starting to learn how important the emotional aspect is. Focus on that instead of trying to it physically better.
Ask her about the pain, how is it right now?even (especially) if they have already told you how bad it is 100 times today. Tell them you see how much they are suffering and tell them how horrible that must be for them. Tell them you believe them.
When you use your energy trying to make things better physically you inevitability make things worse if they don’t feel heard and seen and believed.
But please also take care of yourself emotionally, it is really hard to be a caregiver.
Edit: you can actually help them by showing your partner your emotions or even better talking about your emotions instead if pushing your own emotions to the side in order to help them. That could result in you being perceived as uncaring robot who doesnt take their pain serious.