Tony, I listened to both Pretty Dresses and Wonderful Day and I don't hear the "muddiness" that you say you hear. Your vocals are very clear and pronounced and the volume range is good.
When listening to Pretty Dresses I noticed the instrument's, notably the Piano (not the accompaniment Piano) but your Piano, could have been slightly louder in the Mix. The bass came through loud and clear. The Drums sounded fine to me. The accompaniment instrumentation lacked some sparkle but nothing substantial. All in all it sounded very good.
I think what will improve your sound or anybody's sound for that matter will be a better Sound Card, better Mixer, possibly better cabling if you are not using high end cables, and better recording software. Pro Tools is the industry standard but then again it is one of the most expensive. But the way it is I think your recordings are very good vocal and sound wise.
If we were all millionaires none of us would think twice about getting the best gear money could buy. At least I wouldn't any way.
For now I try to get the best bang for the buck gear, and I sometimes have to do it incrementally.
Unlike Andrea
Best regards,
Mike