LALAMLADY,
Hello there!
The biggest thing I can tell you for sure, is that for many crossdressers the reason for putting on lingerie and or womens clothing tends to change over time. For me, I started at about age 13 some 42 years ago, and there was initially an intense sexual component to my crossdressing. Over time, I started to examine WHY I crossdressed and one of the reasons (I have almost exclusively UNDERDRESSED) is that it has a forbidden element (or did at that time) AND it was a constant "thrill" if you will, to know I had a secret. . I was wearing girls or later womens underclothing. .
As time progressed, I noticed that when I wore lingerie, I was much calmer. Wearing bra, panties, womens shoes whatever made me feel less stressed.
Today, there is little sexual component but lots of stress relief. I think many of the followers here would agree with that pronouncement.