I doubt that many of your symptoms are from the lesion on your cervix, but it seems like a good idea to do a colposcopy on it, and perhaps remove it. Since your Pap smear is normal, it's likely not anything serious, but it's not normal, and perhaps it could be a problem at delivery.
We hesitate removing something from the cervix during pregnancy, because there tends to be more bleeding that when non-pregnant, but it seems like this needs to go.
It's uncertain whether your bleeding has been due to the lesion, to the sub chorionic hemorrhage, or something else. Perhaps removing the lesion will stop the bleeding. But apparently your baby is doing fine.
The cervical lesion may be responsible for the vaginal discharge, which is another reason to remove it.
The pelvic and back pain are not likely due to the cervical lesion, so it's hard to know their cause. It's also a little hard to investigate them much because of the pregnancy. The best time to figure out the cause would have been before you got pregnant, but I realize that we sometimes don't find the cause of pelvic and back pain. At least we try to rule out anything serious. As long as you have a normal ultrasound, and the back pain doesn't seem to be due to back problems, I'm not sure what to advise.
Is it possible that some of your symptoms may be due to stress? When another cause can't be found, that is often the reason.
So I would recommend a colposcopy and probably removal of the cervical lesion.
If your other problems continue, perhaps you might wish to seek a second opinion. Best wishes.