Fuji,
Look on the positive side - you've had your near-hit, or close shave, and got away with it!
Statistically you are now among the safest in the sky!
I had a very similar incident a few years ago, open FIR south of Farnbro's coverage, so no LARS available.
Within 30 feet vertical separation.
So you and I should go flying together - nothing could poss