I'm not familiar with any blood diseases that match your description. So you were already told that your white blood cells were attacking your red blood cells but he didn't have a diagnosis for you?
All I can tell you is it doesn't sound like leukemia or lymphoma. I hope you get some answers soon from your visit with the blood doctor.
Hi, the first possible cause that comes to mind for your photosensitivity is lupus (SLE) :
https://en.wikipedia.org/wiki/Systemic_lupus_erythematosus
Do you also ever get skin problems, like peeling?
Your blood problem sounds like AIHA
https://en.wikipedia.org/wiki/Autoimmune_hemolytic_anemia
The anemia (low number of red blood cells aka RBCs) is hemolytic (the cells are destroyed, or 'lysed' -- as opposed to diseases where RBCs are low because of lack of production). Also, 'autoimmune' as you know means that your own immune system is doing it -- as opposed to something like a virus doing it.
It turns out that SLE can cause AIHA. The AIHA is then said to be 'secondary' to the SLE.
(That's quite a lot to get acquainted with, and there is a risk of a person reading about so many other new symptoms and then developing or mimicking those same new symptoms-- so be careful not to fall into that trap.)
If you have any followup questions feel free to post back. Good luck.