I guess my point was that Crochet is different and one shouldn't expect to be able to crochet just because one is a very good knitter.
It is okay if you have difficulty, just be patient, practice, and ask for specific help when you kneed it. Pick up some easy knitting to wash away frustration. Then see if you or a crocheter can identify what is causing you trouble and offer a way through (different method, clearer example, or step-by-step instruction).
Remember to swatch! One of the best thing you get from a swatch is practice on the stitch, pattern, or method (well, other than a FO that actually fits and looks like it should).
Start out with easy projects like pot holders, dish clothes, scarves, and hats. Use these "swatch like" projects to learn new stitches. After awhile you'll be making doilies and table clothes, blankets and sweaters, orhat ever you like.