Every MBP owner suffers the same fate as you. As soon as you buy one, it simply a matter of time before a 'better' one comes out and displaces the one you have. It is a matter of degree and clearly you are at the high end of this phenomenon.
When I purchased my current MBP, I made certain that I got the fastest CPU available only to be outclassed by a faster CPU a month later. My irritation lasted about a day but I still had an excellent MBP and I no longer feel the least bit envious of any newer models that have been subsequently introduced.
You still have a first rate MBP and enjoy it.