Breast cancer and hep b

Scanzaroli

Anyone out there with breast cancer and hep B? I am a health care worker and was diagnosed with stage 2a her2 pos breast cancer in May. I had double mastectomies in June and before starting my. Chemo had blood work. To my surprise in have evidence of a past hep b infection with immunity, (core anby pos, surface antigen neg) however since I am going to be on chemo, they are recommending epivir,  since chemo could possibly re activate a past infection. They said the risk is very low. I am worried about taking yet another risky drug all while on chemo. And I hate to admit, I read the side effects about changes in fat storage, (can cause a "buffalo hump" and back fat while reducing facial fat and extremity fat). I am feeling badly enough about having mastectomies, rapid onset menopause after stopping hormones, now soon to be bald. I'd like to keep my fat exactly where it is thank you. Anyone else have anything similar.