Missing your ex doesn't mean you should get back together with your ex. It's normal to miss the little things about dating him, even if you know that you two aren't meant to be. That's why you shouldn't start doubting your decision to end the relationship. It's normal to miss some things about your ex, especially these things:
Even if you weren't sexually active, you probably loved the feeling of your ex's lips touching your lips, or how his body felt against yours when you would cuddle in his bed. Of course, you can get that type of physical affection elsewhere. You can invite your puppy or bestie to cuddle with you on the couch or give you a big hug. And when it comes to sex, there's always masturbation.