According to Ayatollah Sistani, the age for menopause is 60 years lunar calendar (58 years Gregorian). Are you seeing istihadha bleeding? If you are seeing istihadha for menopause then is your age over 58? Discussion of menopause in medicine is different from that of ahkam. As per fiqh, if your age is not of menopause, then the ruling on bleeding will depend on the conditions of the blood.
However if your bleeding is continuous for at least 3 days and maximum 10 days and for the first three, blood is present for 24 hours with not even 10 mins of being paak (even if the blood is present inside the vagina and not necessary for it to come out continuously it will be enough for haydh), then this will be haydh and the month after as well you can have haydh.
However if it is not as above bleeding will be istihadha. The spotting would be istihadha qaleela. As for the heavy bleeding that happens twice, for example it happens at 10:00 in the morning and 5:00 in the evening. Then for zuhr and asr you'll have to do a ghusl and for maghrib and Isha you'll have to do another ghusl.
When the bleeding is not constant, it will be ruled as istihadha bleeding. Wudhu if is detrimental to your health or is possibly detrimental, you can do tayammum instead of wudhu. For tayammum, you can use even a stone and not necessary for it to be dusty