They are married and these types of problems are common for couples together as long as they've been. Don't be so quick to trash their marriage, everyone.
OP: tell her, clearly & calmly what you want from her. Then listen to what she wants from you. Tell her you're prepared to discuss so long as she keeps it civil. Then go from there. Negotiate for what you want.
Or, if there are no children, you can try your hand at divorce & doing the whole thing all over again with someone else.
Good luck with that.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh