Hope you don't mind me adding in here since I am old - ha!
You do that because it is part of our human nature to want to be in control and feel helpless and worry when we are not. No matter how long you have been a Christian, these are things that happen to all of us.
I am not saying it is hopeless, it is a matter of when you catch yourself worring and freaking out - just hand it back to Him again, and again! God understands and He always takes care of the details when we allow Him too. I think He sometimes laughs at us in a loving way when we blindly try to take it back again. Like we do at a toddler trying to do something on their own that they can't - it is cute but we know they need our help, sometimes it is best though to wait until they ask for it.
I have told God a couple of times "Ok, I really want to trust you with this but I know my nature and when I forget and take it in my own hands again or am worrying about it, will you please just take it back in case I am not thinking clearly enough to hand it back to you?"
