Start small, and tackle one fear at a time. Maybe start with "attacking" a curb, an exposed root, or a particular section of trail that gives you the most trouble. Carrying speed through corners is all about maintaining traction and shifting your center of mass, which requires a lot of flexibility. Perfecting many of your other skills will help you gain confidence in the corners, but as you get older this skill will most likely deminish. Bunny hopping isn't as easy, either. I suggest learning how to unweight the front wheel with short manuals at slow speed. Once you have mastered that, then you can work on shifting your body forward mid stream and unweighting back tire in tandem. You are definitely not alone, and being new to MTB without any previous history, leaves you at a disadvantage. I don't want to discourage you, but just realize that you will need to start from scratch, and practice plenty.

Hope this helps, good luck!