My cats are intolerable

I have 3 cats. My first is a female, about 6. The second is a male, about a year younger, I think. The third is a one year old male.
It is getting to the point that the female cannot tolerate either male. At times, she attacks them and vice versa. The younger male, I think wants to play but she wants no parts of it. I have cat fights all day long-swiping, chasing, cornering, fighting! I can't tolerate it anymore.

On top of that, my cats are well-fed but they're ALWAYS hungry. They don't have worms. They are all a little oversight and they're not losing any weight. The vet has dissuaded me from testing for thyroid problems. My olde male is the worst. I CANNOT keep him off the counters, out of the recycling can, which is under the sink in a cabinet with a lock-he climbs through the other side. I can't cook and I absolutely cannot eat a meal without having to put them down off the table when I'm eating every 5 seconds. They stick their paws in the food on the plates, they steal food right off my plate. These cats are out of hand, and with all the inappropriate behavior, I literally feel like I'm having a nervous breakdown. All I do everyday, all day long is break up fights and chase cats away from the kitchen and the table. I'm at my wits end with them, not to mention the damage they've inflicted on my furniture and the rest of my house!
I've tried putting extra scratchers out, I have tried different methods of keeping them off counters but nothing works.