Seems pretty manageable. Make sure to check for fluid build up in legs…”allergy” cough/chest feeling could be fluid on the lungs.
Balance out the diet/sodium/fluid intake. Probably get on some type of diuretic. Get a normal schedule with a local heart clinic. Should have good success and feel good about things in a couple of months. Hopefully.
Also - the “no symptoms” to serious was probably months of build up. At least that’s what I’ve seen from people around me. Their “normal” isn’t quite normal…seems to take a lot to feel ******, even though things are/were getting ******.