If the new (now resigned) drummer and guitarist#2 are people you think you can work with and they're into the music you write, maybe you need to keep them and dump #1?
You, #2 guitarist and the drummer might form the nucleus of a new band and you look for another guitarist if you need two.
Even if guitarist #1 isn't slagging you of behind your back, (though he probably is) you're suspicious that he is and that will kill the relationship eventually anyway. You might as well make the break now and try and salvage the rest of the band if that seems worth trying.
You, #2 guitarist and the drummer might form the nucleus of a new band and you look for another guitarist if you need two.
Even if guitarist #1 isn't slagging you of behind your back, (though he probably is) you're suspicious that he is and that will kill the relationship eventually anyway. You might as well make the break now and try and salvage the rest of the band if that seems worth trying.