is it ever too late in life to explore your sexuality?

Here goes. I'm a long time married woman, mother, grandmother in a heterosexual relationship. For many years, from my teenage years in fact, I've wondered and thought and dreamed "what if" I was free enough to be with another woman. I think I'm a coward. A pussy. A sellout basically because I just went with what I thought was what was expected of me. More than that, I chased what I expected of me. I made this life for me. It's all on me. And yet I yearn and wonder "what if" and "if only". I wish I could separate myself from my identity, from the mom, wife, grandmother, everyone knows me as (who I know me as) and see what other happiness there is in this life. Because truth be told this life has not satisfied me. God, I feel ungrateful saying that, writing those words. What is wrong with me? Am I stupid? Selfish? Fucked up? How do I manage these feelings that won't go away? They just don't go away. I feel attracted to other women. Always have. I don't know what to do or make of it.

Sorry. All of this feels so lame. I'm glad I'm anonymous.