Looking for “fairness” or “equality” in marriage will lead you right to a power struggle disaster. A much better recipe than the 50-50 myth is the 80-20 “got your back”.
The concept is straight forward: In any moment of stress or difficulty determine who’s got 80 in the tank (feeling strong, confident, etc.) and who’s got 20 (weak, sad, discouraged, etc.). BE HONEST. We all need support at one time or another. The 80 then supports the 20 in whatever way helps fill their tank. Switch roles as necessary.
What happens when you are both 20 or less? Acknowledge it together. “I just don’t have anything to give right now”. You may need to seek support from others: Friends, family, clergy and perhaps professionals before you can find each other again. Nothing wrong with that, in fact, it’s what healthy couples do.