When will you be ready to date again

I Know I have only been broken up for a few months now but sometimes I feel like yep I want to go out and start dating and then there is another part of me that just isn't ready especially when you dated a narc ex and he pretty much destroyed your self-esteem and trust etc,etc. I see so many happy couples and I sometimes wish I was in a relationship but again once you lose that trust it is really,really hard to start dating again. So....When do you know you are fully ready to start dating again?? My friend keeps encouraging me to start dating again to heal and get out of my rut but I don't think I am ready yet and she keeps saying go to these singles events try online dating ( That's where I met my narc ex) I just do not want to get burned again.... I want to move forward but I still feel sad sometimes....