Mugboo - MemberOP has been on a skillz course or two and I'm a better rider for it but this stuff remains my nemesis. I'm fine with slow and thrutchy in the dry, poor once it gets proper slippy.
Find a section of trail that embodies this "nemesis" of yours. Three or four corners with whatever slippery steep features you dislike. Ride it repeatedly. Aim to be slow but smooth, then build up the pace. You'll get there.
Also, whilst it most likely not the bike, it might be worth playing with your set up to make sure that your bar angle, brake position and stack height are correct. Also make sure that you're not running your fork too soft - this can lead to diving on the steep stuff, pitching you over the bars, steepening the ha and forcing you to panic brake. All of which leads to a feeling of fear and/or going out the front door.