So this is for anyone who comes looking for a solution.
I finally managed to solve the problem.
The problem was with \AppData\Roaming\RStudio folder
I renamed the older folder and let Rstudio create a fresh file. You do this by renaming the old folder and merely restart Rstudio and it will create a new folder
Then like magic Rstudio loaded-up
Unfortunately, this was the only thing that I did not do in all my prior attempts!
I'm glad you could fix your issue, just for clarity, what you have done is resetting your preference config file, this will set preferences to the default values.