It’s best to reassure when they’re obviously upset, and keep up the positive messages you give them about their self-worth. Teens’ feelings come and go like the wind, and they may be over this before you know it, so we don’t want to keep them stuck.
Avoid saying, “I understand” – even if you think you DO understand, the words, “I understand”, are rarely useful. Instead, show your teen you understand by reflecting back to them things they are saying, or telling a story of a break-up you had as a teen and how you were feeling at that time. (e.g., “I remember feeling like I’d never meet anyone after so-and-so and I broke-up”)
Realize they may not want to talk to you much about it, and that’s okay. Make sure they get the message that you’re available to listen or talk if/when they’d like.
If you mean it, tell them they can wake you up at night if need be - hopefully that won’t happen often, but the feelings that come up when the house is quiet can be daunting with no one to talk to.
Give them lots of love – hugs, affection, encouragement, positive messages about who they are and their attractiveness (I know, I know, that last one sounds bad but it’s not uncommon for teens to feel ugly and unlovable after a break-up)