Your father is having chronic obstructive pulmonary disease
) The name iteslf implies the condition. May be mild.moderate and severe. The causes are so many which need not be discussed now. He has lost weight. Any fundamental cause for COPD is there, it has to be treated first, to give some of relief in his breathing. Not able to take few steps shows the severity of the condition.
1) Keep 02 ready in your house for emergency and for routine use for few hrs a day.
2) breathing exercise
3) good airy optimum temp atmosphere
4) always keep the bed at 45 degree elevation some time 90 degree may be needed
5) mild sedation in the night and broncho dilaters, even cortisone- after consulting family physician
6) Don't leave him isolated
7) keep him engaged like keeping a TV in front of him
Rest as per advise of your family doctor