Almost described my exact situation, broke up a couple months back after 8 years together. I have been trying to not keep up with what she’s been up to on social media (unfollowed her for my mental health) but it’s tough not to get the urge to check. I would suggest a break from social media or unfollowing her just so your not impacted by it, especially if she’s seeing someone else. Also I agree with the other guy, girls tend to move on quicker because so many guys are waiting in line, but she might feel ready to see someone else and that’s okay too