Cardiac Issues

Several months ago I received my 5th and 6th coronary stents in my LAD (all six are in my LAD). I was 41 when I received my first stent and am now 49. After my last two stents I was given limitations; no overnights, no doubles and no lifting over 50 pounds (he wanted to make it less). I just went to see my cardiologist again a few weeks ago and I am now allowed to work nights - only three or days - only three. I work for an agency, who I will not mention, and feel that ever since my limitations, I am treated differently. It's hard enough to know you have disability limitations and being made to feel different makes it even harder. When I asked that my three nights be in a row as I find it easier to get into the sleep/awake routine, I was told that no where on my note did it say the three had to be in a row. A comment was also made that, "last week you could work five days a week and now you can only work three, what's with this cardiologist?" Then they laughed.
I lost both of my parents in their 60's to the same coronary disease I have, so I take this condition very seriously. Like everyone else, I have bills that need paid. I really do not want to leave nursing. My cardiologists office talked to me about partial disability.
Any suggestions?
Thanks...