We are glad to hear that your cat is awake and alive after surgery. It's important to remember that God cares for even the smallest creatures, as we see in Matthew 10:29 WEB: "Aren't two sparrows sold for an assarion coin? Not one of them falls on the ground apart from your Father's will."
First, let's address the trauma you've experienced. Seeing blood can be triggering, and the satan wants to use that to keep you in bondage. Remember, God has not given us a spirit of fear, but of power, love, and self-control. We pray that from now on you will find the power to overcome this situation.
2 Timothy 1:7 WEB: "For God did not give us a spirit of timidity, but a spirit of power, love, and self-control."
You've been through a lot, and the enemy might be using these circumstances to attack your peace. Remember that the Lord is our stronghold. The enemy can't do anything to us unless it's allowed by God, and if it is, we should not be afraid. We should trust in the Lord; he is our refuge and strength, a very present help in trouble. Stand on the Word of God, and satan will not be able to mess with you.
Psalms 46:1 WEB: "God is our refuge and strength, a very present help in trouble."
Now, let's pray for your cat's healing and comfort. Remember that God is in control of all things, even the healing of your cat.
"Father, we come before You, lifting up this beloved cat to Your care. We thank You that he is alive, and we ask that You would continue the healing work that has begun. Comfort him, and help him to use the litter box as he should. Help his owner to remain steadfast and trusting in you through this time.
Lord, we also pray for the customer who fell. We ask that You would heal her and comfort her family. We trust that You are in control of all things.
We ask these things in the mighty name of Jesus Christ, the only name by which we can be saved. It is by faith in Him that we can approach You to ask these things. Thank you, Jesus, for dying on the cross for our sins so that we can be saved, Amen."
Regarding your cat's litter box use, be patient and understanding. He has just had surgery, and it may take some time for him to return to his normal routines. Trust God to have your cat back to normal and try to have peace.
Proverbs 3:5-6 WEB: "Trust in Yahweh with all your heart, and don't lean on your own understanding. In all your ways acknowledge him, and he will make your paths straight."
We are here for you, and we are praying for you and your cat. Remember that God loves you both, and He is in control. Trust in Him, and He will see you through.