MAL,I am sorry for being sparse the past couple of days. I am a "chemo angel" - in other words I send out cards and little gifts to people that have approached Chemo Angels and asked for help during their chemotherapy treatments. None of the recipients know that I have cancer as all they have is my name. Chemo Angels is a volunteer group dedicated to adding a ray of sunshine to the lives of those undergoing treatment for cancer. We believe that men, women and
children who are going through the physical, emotional and mental rigors of chemotherapy and/or radiation therapy deserve some pampering and special treatment This project is 100% about others. 
I take care of special requests on the days I receive a request and I receive a monthly birthday list which I send a card to each person on the list with my special little goodies. My July Birthday list arrived on Saturday with 50 requests.
Not a good excuse as I should have worked on everything later in the day but my body shuts down around 4 PM these days.
Now that you have read all that - did it help take your mind off tomorrow? 
Seeing as you have not seen a Dr. for 20 years don't try to go back that long and fill your therapist in on your health history unless it is important to your therapy = major trauma, loss of a loved one, sudden fears that started up in your life after an event.
The fact is admiration and liking for your therapist will wax and wane. This can be based upon a number of factors, such as the type or difficulty of the material being addressed in therapy, the amount of stress you or the therapist may be experiencing, or something else altogether. These changing feelings toward one’s therapist are a normal part of the therapeutic process.
Some anxiety and stress is a normal part of therapy and you will find that you will not always agree with your therapist. Some therapists will push you and challenge your existing beliefs, and encourage you to work toward change in your life. The key is to recognize the difference between a short-term level of stress due to a specific issue you’re working on, or a minor disagreement, and a longer-term, more serious issue that is interfering with your treatment moving forward. This difference isn’t always easy to spot.
Starting with a new therapist, you generally should determine whether you want to work with the professional within the first three sessions. If, after the first three sessions, you feel you have issues with the therapist that haven’t been resolved, it may be time to cut your losses. It is unrealistic to believe that every therapist can work with every client, and vice versa. Simply let the professional know that you’d like a referral to a colleague (if you need a referral), and that you will not be returning. Most therapists will respond in a professional manner, and ensure that if you need a referral, they help with that. Some therapists may ask why you’re leaving, and you’re welcomed to answer them honestly or say you prefer not to say. It is up to you — it is your therapy and your choice in how much of that reason you want to share. Reference: John M. Grohol, Psy.D.
Therapy is about you: You're the boss, and people forget that.
The important thing to remember is that the therapist-client relationship is exactly that -- a relationship.
"You're the co-creator of this relationship. If you go in saying , 'Here are my goals, here are my expectations, my preferences for how to proceed, what matters to me the most,' ~ if you go in prepared and not looking to take a backseat ... you will have the most success. Be prepared to be honest, to tell the unvarnished truth. Anything else is a waste of your time and money.
Don't worry about being nervous, anxious, crying or feeling sad - that is what your there to talk about so share your feelings and don't try to make anything sound remotely wise, just talk from your heart.
Here is a brief article for you: http://counselingwithmarina.com/2013/09/09/what-you-can-expect-from-your-first-therapy-session/
I have been to 5 different therapist over the past 31 years and, yes, I quit one because we were on opposite tracks and I was getting worse instead of better. The other 4 were helpful.
Sending you good vibrations, I'm pickin' up good vibrations for you tomorrow. Good, good, good, good vibrations; Gotta keep those good vibrations a-happenin'. I'll keep sending you good, good, good vibrations and lots of prayers and blessings for your first therapy session to go well.
Love,
Kitt