Developer cum Wantreprenuer seeking advice

I am a 23 year old developer from India. I work for one of the biggest telecommunication companies in the world, where I draw a nice salary and am entitled to a lot of perks. I have also been working on a startup idea, along with a friend/colleague that has now grown into an alpha level prototype. Owing to our inexperience we don't know whether what we have is launch ready or not and think that we need to work on it a little bit more(a month or two) before we launch even to alpha users. The problem is that my day job is killing me. Itsfuckingcrazy! I do not feel like a good fit in the environment for a single moment. On top of that my day job is eating the time that i would otherwise give to my startup or potential startup.Now I really want to leave and work on the startup but there is this one resistive force ('it's the start of my career', 'Its hard to get into such a good company'...'blah')that stops me every time I think of sending my resignation. So I m in a bit of a fix as to whether to be more disciplined and keep building the start up alongside my day job or to quit and start working on the idea full time! Would appreciate any word of advice!! PS: I don't have any liability