Maybe it would be best to find the cats a new home? Maybe you should talk to your boyfriend about giving the cats away?
I would suggest you try going to some anger management classes as well. The problem with anger, is many times the behavior becomes a habit which is very difficult to break. So you need to find a different way of approaching the problem. You need to try and find a way to diffuse the anger in a non harmful way. Running or going for a swim for example would be a good/healthy way to diffuse the situation. Leave the room or the house if you have too. The key is that you learn to control yourself.
A punching bag, would not be a good example, since it would reinforce the hitting behavior- so that would be something you should avoid.
I don't think you are a monster. The monsters I meet are the people who are aware there is a problem and do nothing to stop it. If you are trying to fix your behavior this is a very good start.
It sounds like the cats are very unhealthy and stressed out as well. Most cats do not chew cords unless they have some sort of nutritional deficiency and most cats don't chew their hair out unless they are either really stressed or ill. Chewing cords is a very dangerous behavior- expensive for you to replace the cords and it could electrocute the cats. They may need a different cat feed- most cat foods are made out of crap and are not healthy for your cats. They may need more to eat or a different feed. A vet visit would be a good idea as well.
Here are some wire protectors that you can buy which may protect your wires a little better:
http://www.amazon.com/American-Terminal ... 5N0FBQC94AThe tubing is split down the side so you can push the wires in easily. They have different sizes as well.
Animals tend to make any stress you are under seem worse. My last bf had the same problem you are describing except he thought it was funny to terrorize my cats. Now he has a cat of his own that he takes care of and he doesn't do it anymore. He got help through therapy and by changing the things that were bothering him.
I also wonder what outside stressors you have going on? It could be that you are angry about something else (your bf or your family or your job or maybe just unhappy with your life) and are taking it out on the cats?
The best thing you can do is learn to control your anger, and if that fails, give the cats up. I see people all the time who starve their animals and refuse to ask for help or even accept help when it is offered. If you cannot handle the situation, the best thing you can do is find the animals a new home. The same goes with vet care. Give them up if you can't afford it.
Dumping them outside or taking them to the pound is a death sentence- so I would advise against that.
Best of luck too you.