What kind of guitars are you looking at for your songs? Acoustic? Pop? Metal?

Remember that patch that doesn't sound good as a solo patch may sound good in a mix. Also a good solo patch may not sound good in a mix.

Do you have the free Amplitube installed? Running a Kontakt patch through it can alter the guitar sound.

If you are looking for a particular guitar sound your best bet would be to look at a high end one guitar patch like these:

http://www.pettinhouse.com/html/acousticguitar_for_konatkt.html

https://blog.native-instruments.com/top-ten-best-virtual-guitars/

There are many others. Google guitars for kontakt.

If you give us a clue in what you are looking for and maybe we can help.

PS - I have found that adding external effects to a Kontakt sound is much better then using Kontakt's internal effects. YMMV

PPS- also check here as you may find some good sounding free Kontakt patches:

https://hiphopmakers.com/free-kontakt-library-instruments-patches

Whenever I get something stuck in the back of my throat, I dislodge it by drinking a beer.
It's called the Heineken Maneuver.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware