Well done I hope it goes well for you!
I often think that talking about things is a lot like doing a bungee jump. The longer you stand at the top deliberating the harder it gets to jump. The fall will be the same no matter how long you stay there and the freedom you'll feel at the bottom will still be there. You've just got to be prepared to make the leap. The thing is for me, the price I pray for that freedom is vulnerability. But the more times I make the leap and am caught at the bottom, the bigger the bungee jump I can make. It's a hard journey and I'm sorry you have to take it but you'll be so much better of in the end.
I wish you all the best in your journey. I'm sorry you've had negative experiences of counselling before, I had the same problem as a minor but it has been far more beneficial now its all on my own terms. Good luck