I don't know anything about the size of your uterus or about not having periods at our age. Something must have worked right if youu have two kids!
The only part I can tell you about is the abnormal pap. I just had another one last Monday. If this is your first one, you should find out how bad the abnormality was before you consent to the colposcopy and biopsies. Usually, for mild changes, they will order a repeat pap after three months and proceed from there. They will actually look at your cervix, not your uterus, through a microscope after they treat it with an acetic acid solution that makes abnormal cells look different in the light. If they see anything abnormal, they will take a few tissue samples. That could take care of it for you, but the lab results will tell you for sure. It is a little painful and you may bleed after. You might ask your doc if you can take anything to help you relax or ease the pain beforehand.
Changes in your cervical tissue could be due to the fact that your hormones seem a little out of order or due to a couple of other things. It may not be related to the enlarged uterus or the lack of periods at all.
Make sure you ask a lot of questions of your doc and try to stay healthy to avoid having too many procedures on your cervix. You already have kids, but really, if you can eat right, exercise, avoid smoking and relax, you may be able to avoid some time in the stirrups.
Total abdominal hysterectomy at age 26 due to abnormal bleeding. Kept ovaries.