I recently began seeing a therapist and I felt the same way you did going into it (similar situation as well). I must say that it is worth trying to open up a little, despite your concerns that you would lie (presumably out of embarrassment) or fail to communicate correctly. Chances are that the person you are going to see is adept at dealing with people who may not be able to articulate their feelings- he/she will lead you along to becoming better at it. Just give it a chance, hopefully you'll quickly see how (for lack of a better word) theraputic it can be.