How do you cope with relationship anxiety?

Example: He says he needs to step away bc of both work stress and emotional stress. Also, said I sent him over the edge bc he was bending over backwards for me and it was not good enough which in no way is the case. Haven't heard from him in 2-3ish weeks. His children are in town for 2 weeks and should be leaving in the next few days that he hasn't seen in many months due to a sacrifice he is making for his ex wife. He is waiting for her to move back here with the kids. I miss him and am having a lot of anxiety over not knowing if we are done or what.

BACKSTORY: long time undiagnosed ADHD, anxiety and depression.