The best way to comfort your friend is to be there for them. Check in by text every day or so (depending upon your texting habits) to let them know you are willing to listen. If you normally have a joking relationship with your friend, consider sending funny videos or gifs to help brighten their day. Check in on them. Let them know you are there for them and willing to listen. I’m so sorry to hear what happened. Are you okay? Do you need anything? Let me know if/whenever you want to vent. Build them up and validate their feelings. I admire you for knowing what was best for you and Justin. It’s completely normal to feel guilty. But you did the right thing. Remind them that it will get easier. If applicable, commiserate by sharing your own experience with a breakup. I know it’s hard at first, but it will get easier every day. I’ve been there! When my ex dumped me, I couldn’t even leave the house. Hang in there, you’ve got this.