Prayers for you and your sister. God is the Great Physician. He will care for you both.
Psalm 73 is a good reflection of your situation. The Psalmist looks at the wicked, and observes that, ‘They are always at ease,’ and, ‘There are no pains in their death.’ He looks at himself, and sees constant affliction.
At this point, the Psalmist’s feet come close to stumbling. His faith in God is in jeopardy. Not until vs 16 do things take a turn for the good, as the truth of God’s love and faithfulness brings the Psalmist back from the brink.
It’s not a long Psalm, and there is great comfort in it. Blessings on you and yours.
Conclusion:
28 But as for me, the nearness of God is my good;
I have made the Lord God my refuge,
That I may tell of all Your works.