I certainly can understand your frustration with this situation. It sounds as though the fundamental problem is that you have had an anovulatory cycle after the effect of the Depo-Provera has worn off. There are several hormonal regimens available to deal with this situation acutely. It sounds like at least one or two have been tried. Although these usually will abate the bleeding for most patients, occasionally a dilatation and curettage (D&C) will be required.
My suggestion is that you have the D&C now. Not only will this stop the bleeding acutely, but it should help for at least several months by removing the thickened endometrium.
Long term, management would depend on whether you spontaneously resumed ovulation or not. In either case, oral contraceptive pills will shorten/lighten your periods considerably. It often takes several months of use before the oral contraceptive pill will regulate the cycles fully. Until then, there can be some unpredictable bleeding. Nonsteroidal anti-inflammatory medications such as ibuprofen will often help lessen the flow as well as treat any associated cramping.
You have mentioned surgical management such as hysterectomy. Other options would include endometrial ablation. Some women will not have an adequate response to more conservative medical therapy and will require these measures. Most ob/gyn practitioners would consider surgical therapy if medical treatment had failed. In your case, it may be reasonable to try the D&C followed by the oral contraceptive pill before resorting to further surgery.
Good Luck. Please know that different practioners will recommend different therapies based upon their previous experience, training, and individual patient preferences.