Thank you very much guys for awesome guidance. I also have one more doubt. How should I talk to my manager about it? My manager put some serious efforts(time and company's money) to get me there. I am feeling bad about my manager. I don't want to disturb my relations with my manager.
Also, 5 years from now, if you do go on to Facebook and higher degrees, and other things... you may barely remember the names of the people from this job. Your current situation has a far larger place in your mind than it will in the bigger picture of your career and your life, once you have more experience under your belt.
I had this discussion, frankly, with my manager the last time I left a job. It was a startup, with struggles, but a promising future. It was a good place. But I didn't want to follow them to an office farther from my home. So I told him that while it seemed like leaving would be a big thing, that in reality, 6 months later, it would make no difference to them or me. And that was true - they hired other devs, I got a different job, everyone is doing fine.
In short, you just need to make this decision for yourself.
A good manager will support you and if you explain your reasons for leaving will either try to find a way to fix problems and provide you with those same upsides where you are; or if that's not possible (for instance, your reason is that you want "Facebook" on your resume), will be supportive and maintain the relationship because there's always the possibility your paths will cross again in the future.
A mediocre or bad manager can be mediocre or bad in any number of ways, and any advice would be highly situational and specific. The only general piece of advice I can offer is to express appreciation for the opportunities you've been given and to make it clear that your reason for leaving is not something you blame your manager for.
You should expect this move may damage your relationship with your manager permanently, but that's life in the big city. You have to do what's right for you, not what's best for your manager.
Having an open conversation with your manager will help build or preserve the trust in the relationship in part because you are including them in the decision that you'll be making.
Your manager cares a lot about you and your career. They will probably be supportive and it gives them an opportunity to provide feedback, will give you opportunity to share your appreciation too.