You need to see your doctor. Your uterine lining probably got built up much during that 10 years when you had no period. Now that thick lining is causing the bleeding.
Cancer might be possible, but it's more likely that it's just thick lining.
Your doctor may wish to do an endometrial biopsy (thin tube through the cervix to sample the uterine lining). That would rule out cancer. Then some hormone pills will help to clean of the uterine lining and stop the bleeding. Best wishes.
A D&C would be one solution, because it would stop the bleeding plus give the diagnosis. It's usually a fairly simple procedure, and you'd have enough anesthesia so that you'd have no pain.
But either the D&C or the endometrial biopsy can be done while you're bleeding. There is no use in waiting for the bleeding to stop, as it could be a long time.
The D&C gets it all over quickly, whereas the biopsy and then hormonal treatment take a while for the bleeding to stop.
Please see your doctor so you can get it taken care of.
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