Been Married With My Wife For The Past 22 Years.

Been married with my wife for the past 22 years. I am beginning to feel my wife's vagina has increased its capacity hence I penis feels like floating in space rather than rubbing against something. I do not know if my penis is shrinking in size or my wife's vagina is expanding.

Please advise also how I can rectify this problem.

Due above reason I love inserting into her anus because it is tight and nice.