Did you marry her hoping you'd accept her as is over time, or hoping she would change over time?

I'm sorry I don't mean to come across as rude or anything, but I'm guessing you realized she was unaffectionate/stoic before you got married(?) So I'm not quite sure what your pre-marital thought pattern surrounding this was...

I don't have any advice, but I do have some insight.

My mom is as you described, my dad was her polar opposite, but for 43 years their relationship flourished anyway. Why? Daddy accepted that due to how she was raised, mommy was not huggy and handholdy, while mommy accepted that daddy was super affectionate and would steal hugs and kisses from her every so often.

Infact its a running inside joke that hugs are to be stolen from her, unless you're 10y.o and under.

My point? This (whatever you want to name it) is your wife's personality, a personality that you were (presumably) well aware of 15 years ago before you married her, and married her anyway... Is it fair to now ask her to change the type of person she is because you can't stand it anymore?

If her personality was disordered (as mine is) I would suggest therapy, but in all honesty, I don't see any type of disorder, I just see a marriage between seemingly incompatable partners.