Inah, my heart goes out to you. not every man will treat you like this and this guy is a total loser. believe me i know exactly where you are coming from as my wife and the mother of my 3 sons has done almost the exact same thing to me and at 30 i find myself on the scrapheap. dont change anything if you dont want to, women are not the only ones who can get walked on. you and i both married cheating jerks. unfortunately it happens. but i know exactly what you mean. it is so very hard to pick up the pieces. dont go making wholesale changes to yourself - the thing you change might ruin your next relationship.
I know it is hard and you will doubt yourself - i do everyday, the rage the loneliness and despair - feel them and heal, if you didnt feel them you wouldnt be human. But be yourself, be assertive and stick up for your needs, but dont ever be something other than yourself.