The shidduch crisis isn’t part of the Jewish religion. We have 613 mitzvos, and one of them is NOT “thou shalt freak out over the age gap.” That would seem to be even more bal tosif than the notion of needing to cover your face in front of men at your wedding.
/stupidreferencetodifferentthread
In short, duh no you’re not a kofer. You become a kofer, IMHO, when you believe so much in the shidduch crisis that you lose any hope of finding a shidduch and forget that it’s actually in the hands of Someone higher than statistics.