1. I noticed that when I'm in my toe side, turning to heel side, it goes really fast, and before I know it, I'm already on the other side of the slope and have to turn back to toeside or else I'll hit the trees on the side. I ended up skidding my turns alot and have to side slip to slow down in order to be confident enough to initiate another toeside turn.
This does not happening the heel to toeside turn, everything's pretty smooth. It's almost like my turn from toe to heel is too quick and my turn is overshoot upon completion,
2. I freak out to imitate the toe side turn. I know I'm on the back seat, but I cannot for the life of me to lean down the slope because I'm afraid of gaining speed. What can I do to overcome this fear? Sometimes when I do have the courage to do so,I out weight on my front leg while keeping my rear leg heel edge dig in, the boards starts turning and it turns beautifully, but that's when I'm possessed and not freaked out.
1.It sounds like you are rushing your edge transition. If you changes edges before your weight transfers over to the other edge, you can kind of get "stuck" with your board still turning, but your upper body is still lagging (and when your body is counter-rotated or twisted, it is hard to do much of anything until you untwist it). Try focusing on going from toeside to flatboard (for just a moment), and then to heelside to make the edge transition smoother.
2. One way to slow it down is to go completely perpendicular to the fall line (across the hill). That way when you finish your turn, you aren't picking up anymore speed because you are not going downhill (this give you a little breather before doing your next turn). Here is video of my wife doing big S-turns down a decently steep slope (this was early in her third season of snowboarding). You can see because she starts and ends her turn coming across the fall line - she really isn't pick up a lot of speed despite the steeper pitch of the slope. When doing this... it is IMPORTANT to LOOK UPHILL
with your peripheral vision... because some people might not be paying attention and plow into you. You can see my wife keeps her head pointing in the direction she is travelling (not always pointing downhill) so she can see uphill out of the corner of her eye.
To slow it down ever more you can do garlands. Check out the video below
If you feel in control of your speed, you will feel much more confidant. Hope that helps.