Insecurity

So I was just thinking here, bored at work, end of day, and the only thing my exN complained about me for the last several months was my insecurity. Now hear me out - if I was insecure (and I am sure that I got worse over the years) wouldn't a decent boyfriend/husband do things or say things to reassure his partner? This is common sense to me. If someone came to me with a problem about being insecure, or anything like that, I would be there to back them up in a heart beat.
So the ex tells me that I was a horrible girlfriend, that ruined everything, including his life because of my insecurity. The only thing I can do about it now is laugh. I've told him hundreds of times that a relationship is like a flower, you have to feed it, water it, love it, put it in the sun, and out of the harsh elements. It makes so much more sense to me as more time goes on. NC is really the only way. I have realized so many things, and my eyes are more open. One day they will be wide open and living again to the best of my ability, 100%.