I've been trying to get my cardio back so I'm starting to row again. Last winter I did that and it did wonders for me and my breathing during wods last year. I think it helped some physically but really helped mentally. Basically made me realize that yes this sucks but you can keep going.
Last year when I did it my rowing for was pretty shitty. I knew it was shitty and knew what I needed to do to fix it but just couldn't make that brain body connection at first but then it clicked.
Now I have strong pulls with strokes per minute of about 20 consistently now but my problem is I can't speed it up for springs. I guess there's worse problems to have though.