I am 54 and have entered menopause from last 1 year.
Two weeks back I experienced a bloody discharge just as a spot. After 4 days experienced the same thing and now from this week I am going through painfull bleeding but not much.

What should be my line of treatment?

I have four kids didn't face any problem of infertility and had regular menstrual cycle in past.

But during my first pregnancy gynecologist told me that I had a fibroid and assured me that it was going to degenerate and also I didn't experienced any of its symptom till menopause

The fibroid obviously did not degenerate and is irritating the lining of your uterus, not uncommon and one of the symptom is bleeding. Check back with your doctor for the way to proceed with this.

The first action of treatment is to have a check up and make sure you express all your concerns to your doctor.