Vertical lines & unresponsive screen after a drop

Hello.

I have an issue with my iPhone 6 Plus after a recent drop - the screen has vertical lines and is almost entirely unresponsive (when I slide a notification on the screen I see that the swipe is recognized though) and I cannot get through the lockscreen as the Touch ID is disabled after rebooting and you have to put in your passcode manually and that does not work.

You can see the wallpaper with the lines on them and then shortly afterwards all the lines cover the entire screen, then the screen goes black.

Worth of mentioning is the fact that the screen was replaced by a third party a year ago or so as it was heavily cracked in places - but it still responded to touch even after that.

I've watched this YT video - https://www.youtube.com/watch?v=ny8mHGHX... - and took apart my phone as per instructions and made sure that all 4 of the connectors are properly secured - they all were and unfortunately the issue is still present.

This was my first attempt at DIY and although it did nothing I am not discouraged - I would be very grateful if you could point me in the right direction as at this point I simply have no clue what to try next. I am short on cash so buying a new iPhone isn't possible but I think I could afford spare parts, unless of course they cost almost as much as a new phone.

Also if there are any users from London here, any idea how much it would cost to get that fixed by someone?

Cheers.