As I understand, you have two options, If you want to go to IIT, I will explain positively both of them with whatever understanding I have.
1) Take a job and keep preparing for GATE
The only positive thing is that My brother used to say that do not try very very hard anything. He says if you look something very close then it becomes blurry. So keeping things at appropriate distance and priority, is very important.
Getting a job will definitely loosen the heat, which you have currently. One more benefit is that you will understand that without IIT, there is no life, then you will start preparing with more interest and concentration.
But there is only one disadvantage is that, if you start enjoying your job, or you feel comfortable then forget about IIT. You keep adjusting, feeling like "Ye bhi to thik hi hai". Then IIT dream will be transfer to your son. :D :D
2) Leave that startup job too and prepare full time again with more focus
Start once again this time, more seriously, with defined aim and focus. You have 800 Rank, you deserve better. If you have belongs to any reserved category then you would have got interviews call from all the IIT for at least for MS.
Do not loose the patience, you deserve to be in IIT. It's just a matter of 4*2 Marks questions. If you quit only for 4 questions, then you may never forgive yourself in the coming 40 years of your life. It seems very difficult putting one more year, but believe me, the next 40 will be legendary. Believe.