Here is a rough timeline.

Initially I could only do diaphragmatic breathing (with air pillow and without) and walking for 5-10 minutes so I started with that.
I gradually added other things. The very important rule is to never do any exercise that increases pain as this makes the injury worse.
Edgelow's idea which I found working for me is that diaphragmatic breathing relaxes the muscles and reduces pain. If it don't feel the reduction in pain
after 5-10 minutes then maybe it doesn't work for you. But if it does reduce the pain and if you do it all day every day, then you let the injury heal.
But you must not lie down all day. This is why walking is important.
I did the exercises as many times a day as I could. As I could not do anything else, finding free time wasn't an issue.
I also did relaxation exercises. Basically lying on my back in a dark room twice a day for 40 minutes or listening to relaxation music
and trying to relax all the muscles.

I also did do some chin tucks occasionally, but not every hour as per Edgelow. Also for the first few months I did longus colli strengthening.
But I suppose this was not a big issue for me so later I only did it occasionally and eventually dropped it.

In a couple of months I added rib mobilization with a pinkie ball on a stick. I am not sure these were very useful.
I walked at least 3 times every day and gradually increased time to 20-40 minutes per walk using pain level as a guide: if the shoulders start to hurt, I walked too far.

Month 4: I added ball exercises (diaphragmatic breathing on a ball). I only did these once a twice a day for a few minutes: these seemed less useful that breathing on the back.

Month 5: I added spine mobilization with a small foam roll. At first these were OK, but after a few weeks I started having numbness in my feet. As I found out later, I had L5 vertebrae fracture and herniated discs and mobilization was apparently aggravating the nerve roots.
I stopped doing the foam roll mobilizations, but still have some on and off feet numbness 6 months later. Getting better though.

Month 6: I was able to add big foamroll stretches. 5 minutes 3-4 times a day.
These are good as they stretch all the chest muscles. Could not do them before due to increased pain.

Month 8: Added doorframe pec minor stretches. Had to be careful with these as they cause hand numbness if I stretch too much.
These were quite painful initially so I only did them for 10-20 seconds a few times a day. Gradually increased to 60 seconds at a time multiple times per day.
Also did some ball exercises. Only did these once a day for 3-5 minutes. The more useful of this is the one where you lie with your back on the ball and
feet on the ground.

Month 10: added neck stretches on a foam roll. I don't have the wedges so I did not use them. These were also quite painful so I only went to the
point of pain, not past it (this is what the wedges are meant for). Gradually these became less painful and are almost pain free now.

At month 12 I was continuing diaphragmatic breathing, foamroll chest/neck stretches and some ball exercises as well as walking.
Later I replaced diaphragmatic breathing with abdominal crunches and added a bunch of other pilates-type exercises.