Since you are a diabetic and post menopausal ,the cause for thickened endometrium
dpshould be found out to rule out endometrial cancer
.Similarly bulky cervix
should also be explored o rule out malignancy.
Nabothian cysts are normally harmless and their investigation is done if hey become very big.
Your doctor is perfectly right in asking for the biosy.
You are highly anaemic and probably repeated on and off bleeding and poor diet is the cause for it.
Get your biopsy
done as early as possible.