Overwhelmed

Lately I've been feeling overwhelmed and I keep crying at the thought of my ex. We stopped talking in May and I've had him blocked since june. He's a narcissist and my best friend made me end things and block him because she didnt like how I was being treated (I dont blame her). I know that hes no good for me and things will get better but idk how to keep going like this. Idk what's happening to me and why I'm feeling this way. It's suddenly such a strong feeling. I've also dealt with depression since I was a teen so that doesnt help and I have 0 motivation to do anything except mindlessly watch Netflix + we're still in lockdown. Have any of you felt this way? Do you have any tips on dealing with this while in lockdown? I am working from home but even my job is terrible having to deal with my micro managing leader and rude customers but I am grateful to have an income because I know a lot of people are struggling so I cant complain about that.