You need to start thinking positively about things and not think about the negative things, try and keep yourself busy so that you have less time to think about it. Try accompanying yourself with people that make you smile. Hope this advice helped, and you soon become happy.
I'm no expert on relationships, however I have broken up with my sons father after 5 years. It was hard, I realized a lot when we broke up, I lost so much of who I was. I think it's important you make time for yourself. Do things you enjoy, maybe get your nails and hair done? Maybe a little shopping. Make yourself a priority. Maybe when your ready socialize a little more. Don't sit and dwell on the past, look forward for you future.