You describe classic heart failure symptoms, but as you mentioned they can also be a sign of other conditions. One is anything involving the lung and the other is anemia. Those two should be ruled out with a simple xray and blood work and of course you will need to have an
echocardiogram to assess heart function because I still think that this is the most likely explanation.
My BP has been on the low side all of my life and is only very slightly elevated now....almost normal!! LOL But that doesn't fit the profile for CHF though I suppose there are exceptions to every symptom checklist....