I do recall that many people recorded success with using paper or any other thing to press down the connectors for camera and ambience/proximity sensors (which in turn adds pressure to the big chip at the back(processor).
Since my phone has fallen countless times (at times from a distance), I assumed some components must have partially detached from the motherboard and cause the issue.
So I got a friend's soldering rework station heat gun and soldering paste.
1. Applied paste to the two connectors for the screen as shown on the first image below and reheated them properly then allowed it to cool.
2. Applied paste generously to the main chip(processor) as shown on the second image below and fired it up before letting it also cool down.
Remember that my screen refused to open throughout the day, haven't been able to use it for almost three days. Once I coupled it and started, walah!