Whew. What a trip. I think you should be feeling great about getting all the climbing done while so sick. The difficulty breathing at night is called Cheynes-Stokes breathing and is very common when one is not acclimated. So that’s a sign that you were pushing things. My guess that fatigue was catching up with you on your last climb and that made the symptoms worse.
You certainly had all the classic signs of AMS on the decent and car ride back to town.
Chest pain is not normal with altitude though. I’m no doc so take this for what it is worth: Your symptoms sound a little like pulmonary hypertension. I’ve seen that in high altitude climbers fairly frequently. You might want to get this checked.