Hello, I was hoping someone could help me with a cactus question. I have an old man cactus that was left outside in the sun for too long. It is sunburnt. It was also attacked by Mealy bugs. The mealy bugs deformed it close to the top and the area looks to be shrinking. There is still green at the top but I'm wondering, should I prune it at that spot or just leave it be? I've attached photos and thank you for any help!