"But you even don't know what a situation I'm in!", you argued. True, I DO know little about you. What I know is things that are common to all of us, and those things are enough to prove that, your job is good. And the reasons are:
1. You chose this job.
It was around years ago, or months ago, when you got 2~4 offers. You carefully compared them and realized the fact that there's no perfect job. Finally you decided to go to the one you think best. At the time you were still romantic about careers so you started to plan about it. You thought you could do A, B, C and D and you would get E, F and G. They were so wonderful and you were so excited, you couldn't wait for the second morning.
Now several years has passed. You never do A and B, to say nothing of C and D. Think about your current situation, is it still possible to do them? If it is, you still have chance, your job is good.
2. Your boss pay you.
And less than what you contribute to the company. It's always like this. Never expect the opposite.
Remember that if things are fair, everything will cost more.
3. You get money.
You are complaining about loosing balance of life and work, aren't you? Then you should be reminded of the truth that you need money to live, and you work for money.
4. Your colleague/customer/boss is not the worst one in the world
Think about the past, it's common that we hate someone. But the bad idea is that the world will be much better as long as you don't see this annoying guy. Even with the guy you like most you know clearly some quite bad habit of him.
5. There are many ways to make a change
Are you just bored by repeating the same job everyday? Or you think there must be some change on you? First think back to the plan you made when you just joined this company, are they still possible? Learn from a colleague in your company that's happy and successful, be open mind because his success is likely to be copied by you.
Finally be clear that just your job is good doesn't mean you should stick to it all through your life.