Weird enough, that pitch (D2-G3) is pretty much my comfort zone... If I go an octave higher, I get lost. Actually, if I start to hit middle-Cs and beyond, things start to go bad...
If you browse through my Soundcloud, you can see that all my songs are sung in the Arnaldo Antunes / Leonard Cohen range (these 2 dudes are my biggest inspirations to sing).
I'm gonna definitely purchase a membership or some reviews to try and investigate the origin of this problem further.