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

I think my wife has started to show the first signs of dementia.
She said she can't remember what she ever saw in me!

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