How can I meet someone?

My ex girlfriend broke up with me a year and a half ago. She is still my best friend and she is now with a new guy and they are getting very settled. I still love her as much as ever I did, but I realise now it is time to move on. We have kids together and I am very lucky as I get to see my kids whenever I want which is lucky me, every day. But when she broke up with me my confidence was shattered. I now find it really hard to ask anyone out. I have been asked a couple of times but because my ex girlfriend is of super model beauty I have become very choosey. I'm also petrified of rejection.