It would appear that your roswe bush has a bad case of fungus--Black spot accounts for the big blck patches and rose rust is the brown spots. You need to purchase (unless you already own) a rose fungus spray and follow the directions on the label as you spray. You can give the rose a spray at two week intervals three times total: as soon as possible and then twice in the next mont

You are quite welcome. Good  luck  with defeating the fungus. marjorie