Help me with my sick Cactus please

[wayoutwest302]

Ive noticed that something seems to be eating part of my cactus, but I dont see anything on it. Also, there is white looking spider web coming out of where the thorns come out of. Can anyone please tell me what is wrong with my cactus. Also when you squeeze the cactus with two fingers, it feels weak/ mushy now, not solid like it used to.

[StarDragon]

If this is a species of Pilosocereus, then filaments growing from the areoles(fuzzy spots where the spines grow) is normal. Pilosocereus means hairy spine.

[wayoutwest302]

I believe its a cereus peruvianus, thats just a small pict of them. There almost 4 feet