Shrink etiquette

After meeting my friend Babs for lunch today, I whipped across the street to drop some stuff off at the post office. As I was getting out of my car, I ran right into my former therapist who I hadn't seen in almost 2 years! We hugged each other and she walked with me into the P.O., but it was kind of awkward. I realized I don't know what the etiquette is for hanging out with your ex-therapist. I mean, are we allowed to be "friends"? I was so happy to see her, and I would love to meet her for lunch sometime and catch up -- but is that allowed? Or do I just schedule an appointment? Do I have to pay to be friends? And it's really weird making small talk with someone who knows ALL your deepest fears, weaknesses, evil thoughts, etc. She helped me become the Lisa of Today, and that's HUGE. So how do I just say "Hi, how are you? Fine, fine. Take care!" You know???

Also, I felt weirdly evaluated, like she was thinking, "wow, she's gained more weight, she must still have issue XXX". I know that's ridiculous, but I wonder how I seemed to her in that one-minute timeframe. Together? Mature? Or frazzled and still confused? Should I have played it totally cool and pretended to be "all better" now? Or should I have caved in to the secret relief at seeing her again, and allowed myself to feel the mild sense of loss I got because I no longer see her on a regular basis and she no longer knows what's going on in my every thought.

Am I perhaps overthinking this??? Maybe I really DO need to schedule an appointment...