I tend to give TOO MUCH information to all my healthcare professionals. I want them to know everything. I would definitely tell the new therapist concerns from the old ones. How do you fill out your questionnaire? I told our therapist--when we went in for our six-month check-up--that I was not interested in trying to change my husband but in how I could gain some insight into our dynamic so I could better adapt (or cut loose). I made it clear that I wanted to work on my end, the things that I could control. That approach made a difference. Voicing it kept me on task, because sometimes I actually did want him to see how wrong he was.
Before you go, be honest with yourself about what you hope to gain. Be as specific as you can be. Then, express clearly to your therapist what you hope to gain from your sessions. Voice your concerns stemming from past treatment, and then COMMIT to a certain number of sessions. Ask your therapist to quantify this for you. It's not an exact science, but given your goals and where you are, he/she should be able to tell you about how long it should take to get you "out of the woods". Whatever that number is, commit to it. It won't always look, feel, taste, smell, sound pretty, so you have to be committed to going THROUGH the fire that can be your therapy. If at any point you feel that you are being mistreated, address that in session. Maybe the therapist has gotten a little personal; maybe he/she just hit a nerve with you. Deal with that issue, as well.