You may have to record the "hit" separately, on another track, with a different mic setup, then mix it in later. Or, you could try replicating the "hit" sound with some other percussion instrument that is easier to record.
You might be able to use EQ to take out the offending frequency. Or you could throw in a fast-attack compressor/limiter. Of course, both of these will affect the guitar sound as well!
Condenser mics are super-sensitive, so backing off a bit might be worth trying, although you will pick up a higher percentage of ambient sound (if any) as you increase the mic distance.
-CAG