I don't see the logic in your thinking here. If the goal has been to find a good therapist, and you gave yourself the best opportunity to do so, does it matter where that therapist comes from? Yes, you could have found her/him without the new expensive plan, but you didn't know that at the time. If you don't see therapist #3, the point in purchasing the new plan is that you probably have more options in other health care providers and maybe better coverage/lower deductible. And you have some peace of mind knowing that your options aren't limited.

Next year, if you aren't happy with having purchased the plan, you can go back to the other. I think the important thing is finding a therapist you click with, and it sounds like you've done that. Celebrate!