Oh no! Lost my Developer ID certificates

Due to some issues while compiling, even the Scilab 6.0 was not running on my system, so I had to format my mac.
I did export my certificates to prevent any loss, but still they were of no use.
After doing a fresh install of MacOS, when I tried to restore these certificates, it said they are missing private key.
Also this was not it.
Even I could not create new certificate due to a restriction of 5 Developer ID certificates only.
I asked for my mentors help and even help from Apple support team, lets see what we get.

Hoping for Best.
Happily Coding
Divyanshu Kumar