Hey dude, I hope you'll find a way to give the past some rest and focus on what's needed to focus again on what you need/want personally. Take some time to reflect on what's out there for you. For me personnaly it's been super helpful to go find a new hobby. It opened me up to be passionate about something again, and it allowed me to meet new people. Youknow, it might be liberating to be able to get your mind off of things. It allows your brain to stop worrying constantly and gives you a brief period of mental peace so to say. It's time to shift your focus back to you instead of her. After 3 years you deserve to be happy again.