just beat the hell out of it's fists and tentacles, and try to avoid contact with the smaller enemies until you know you can deal with them
but when 2 enemies suround you and attack you non stop while the boss is underwater, its pain
If you want to hurt the boss itself try throwing cones at it, for the smaller enemies Uppercuts can easily get them out of the way, at least for a little.
How do I do an uppercut?
