I agree with Stu & the others: practice is the name of the game. Here's what I do when I teach manoeuvering to friends in order to increase their level of competence...and confidence: I have them prepare 4 floats (fenders, empty 2-liter coke bottles, etc) with a weight and fishing line attached to each. Then we take the boat away from the marina in an area not too deep (to minimize length of fishing line needed) and with space to practice and move around. We then set the 4 floats to form a square in the water, the length of the sides being 2 feet longer than the boat length. In your case, I'd set them at 30'. This will give you a 900 square feet area with 30 feet sides and a tad less than 43' diagonal.
The idea is then to come in the square, do a 180 using the prop walk as described in previous posts, and then come out off the side you came in. Without touching the floats or stepping out of the square ! Do that from all 4 sides and it will practice you in every position of current and wind.
When you're comfortable that you can do it good without stepping over the sides or touching the floats, get out of the square and immobilize the boat stern-to about 50 feet in front of one of the floats. Then put her in reverse and back towards the float with your goal to bring the boat with the stern dead center a foot in front of the float. Then do it from the other 3 floats and again you'll cover all positions of current and wind.
Once you've you have accomplished this, you can try backing in the square from one of the sides, doing a 180 inside and backing out. If you touch a float, you get out of the square and try again, from the same side that gave you problems.
I suggest first trying this on a calm day and I'll guarantee that it will increase your confidence. Don't forget that the diagonal of that square is about 43 feet, which is more than plenty to turn it around. So when you feel good about it, reduce the square size all the way down to 28' per side. That will give you a diagonal of about 40 feet, enough to practice in turning the boat in its own length without damaging anything. Bow and stern will be right on opposite sides of the square, but it will make you visualize turning the boat in its own length.
Coming into tight quarters or docking under adverse conditions should be made easier knowing from having practiced you can evaluate wind and current wherever they come from. Good luck