My Husband Is 64 Years Old And Has Had Gastric

My husband is 64 years old and has had gastric bypass nine years ago due to excessive weight gain to 380 pounds. He also had numerous health issues compounded by his weight such as pulmanory COPD for which he was on oxygen at the time. Since his surgery, he has lost down to 185 and has maintained this weight for quite some time now. Once he started losing the weight he no longer needed the oxygen so the doctor took him off of it. Long story short, he had been doing well, except for about three weeks ago he began losing his appetitie and bacame fatigued and had a occasional difficulty breathing when he layed flat on the bed at night. He went to see his general doctor this past Monday and they did an EKG and the doctor said it was slightly abnormal but ok. He put him on an appetite stimulant and did some blood work of which we will have results of these tests by Tuesday or Wednesday of this week. He becoming weak from the lack of nutrients and is making himself eat a little and drink water and protein drinks but we do not know what might have caused this all of a sudden. Do you have any ideas?