Woah.. that's a lot.
Looks like everyone wants you to be their own version of you. The worst kind of problems in life are external problems, that you have no control over.
What CAN you do? Let's say you breakup with your girlfriend, fight with your dad and refuse to pay him a single penny, punch your boss in the face, leave everyone and...... then what? sell your worldly possessions and become a monk who lives in the himalayas? That's obviously not the way out. But what else CAN you do?
Let's try handling this one by one.
Job - You can do nothing here, considering it took you a lot of effort to land this one and you need the money. All i can suggest is work hard and try to get a better job at the earliest possible opportunity.
Father - Something I said to another person a few minutes back - just talking to people can be surprisingly effective, MUCH more effective than you think. Approach him, Tell him that you wanna talk to him, son to father. Ask him to give you an hour or more of his time, uninterrupted. If he agrees, sit with him, and talk. Tell him everything you've written here. Be calm, don't get agitated. The kind of person that I think your dad is, he'll take advantage if you show vulnerability (crying or getting angry). Calmly explain to him how stressed out and depressed you are right now. Tell him why you think you should get a chance to dictate your own life.
Too afraid to do the above? Then either run away from home, or drink your alcohol and drown in your sorrows. Please, BE BRAVE and talk to him. Maybe he'll be unreasonable. Maybe he'll shout at you. But don't stoop down to his level. Make a plan of what you want to say to him and just go all out and say it.
About your girlfriend, after all you're telling us, I'm confused.. Why are you still with her if she'd so unaccomodating and her family is so rude. Do you love her THAT much? Please give me atleast 3 reasons.. WHY do you want to still be with her?