Tachycardia and edema

Hi,
My ankles and calves have been swollen every day and my heart rate has been between 125-135 at rest. This has been going on for a few weeks. A couple of days ago, I went to see my GP to check on a case of Shingles, which I've had for about 3 weeks. He was very concerned about my fast heart rate and ankles. I was also having quite a bit of trouble breathing (I do have severe asthma and spent 10 days in the hospital last month with asthmatic/bronchitis.). He sent me right over to the hospital to be evaluated. I was immediately admitted to the Cardiac Care Unit, where many tests were performed, including an EKG and echocardiogram. They also took tons of blood and urine. It was determined that my heart was fine, although for the 2 days that I spent there, my HR never went below 115, even while sleeping. It was also determined that it was not my asthma medication or any of the other meds that I'm on that caused it. I also have severe GERD, migraines, and frequent headaches.

One test that did come back with somewhat of an answer showed that I have very low albumin (2.8) and hypoproteinemia, or very low protein levels in my blood. The doctor said that this was probably not because of diet, but that the protein was "leaking" out somewhere. She also said that it could be an indicator of something much more serious. The hospital took more blood and urine to test, and then discharged me. I still have the swollen ankles and very fast HR (it's 133 as I sit here typing).

My questions are; Can sustaining this tachycardia be dangerous to the heart? What things should I be concerned about with a very low blood protein level? Should I be concerned about cancer? My dad died of Lymphoma at age 49. I'm 47. Could all of this be asthma or GI related? I do have GI issues, in fact I have an endoscopy scheduled for this Monday due to swallowing problems. The discharge instructions mention a work-up for hypoalbuminemia including myeloma and lymphoma, also.

Please help me. I'm a little scared. Actually, I'm a lot scared!!

Thank you!