You're definitely not alone in that Sidony. When I was going to a therapist for agoraphobia and panic attacks, I put lots of thought into what I wore. I did my make-up and made sure my hair looked perfect. It was like I was getting ready for a date. I think it's because of the reason you mentioned -- I wanted my external "fabulous" appearance to make up for what was lacking in my coping skills. It made me feel more comfortable and confident and I think that made it easier for me to open up to my therapist. When I look like crap, I feel worse and it's harder for me to communicate confidently and openly.
For a while, since I was still quite agoraphobic at the time, my therapist's appointment was the only time I left my flat. So, it reminded me that I could look good and presentable and while I was out, I was reminded of how I used to be that way every day -- and how it felt. It was good practice for rejoining the "outside world."
P.S. I have to admit that I did find my therapist attractive, though. I think it was only natural. He was my age, good-looking, agreed with everything I said and told me I was intelligent and wonderful. What girl isn't going to enjoy that?

Since I had been isolated for so long, I think I was just enjoying being in the company of a man as well. So, feeling attractive and comfortable talking to a man I found attractive was good practice too -- one more preparation for when I got better and started socializing again.