Breaking Artists

So I’m painting a picture for christmas, and my first attempt was a disaster. Simple wet on wet landscape (my friend loves Bob Ross), but everything that could go wrong did. My brush fell apart on my painting, I accidentally splattered paint all over my picture, and all of my paint was mushy and ran together like a really bad watercolor painting. My base was about 60/40 Titanium white paint with linseed oil, but the rest was just the paints from the tube, and almost nothing stuck and what did stick just turned into mud. My brushes were really really wet to matter how much I wiped them off, would the excess turpentine have something to do with my liquid mess? And should I try using titanium white with some turpentine and a bit of linseed oil for a base and gradually build up the oils? I replaced my cheap brushes for better ones, but should they be dry while I’m actually painting, except for a bit of a cleaning in between? Christmas is only a week away, I could really use some help figuring this out.