Immunoglobulin defeciency after treatment

I received 6 R-CHOP for diffuse large B cell, extranodal lymphoma (not in lymph nodes).  The largest tumors were in my breasts and a small one on my kidney, also had  "slow growing" lymphoma in bone marrow.  PET scan 6 weeks after end of treatment showed breasts were in remission, kidney tumor was smaller, but "hot spot" on my liver.  Now, 3 months after last chemo, my immunoglobulins are low.  My oncologist told me it was permanent damage to my B cells from the lymphoma.  Any one else have lymphoma caused immunoglobulin defeciency?I've also been plagued by the fibrosis that replaced the lymphoma in my breasts, that is also in my axilla, and causes alot of pain when I use my arm.  Its difficult to tell new tumors from the fibrosis, except biopsy.  Any one have this problem?   Thanks.  Lee