Hysterectomy increases risk of bladder, bowel and vaginal prolapse, urinary and fecal incontinence, fistula and celes (enterocele, urethrocele, rectocele, cystocele). So it makes more sense to suspend the uterus instead of removing it. A good urogynecologist should be able to do this. If you have not gone through menopause then the surgeon may be able to use your own tissues to fashion a "sling" versus using mesh.
Also please see a UROGYNECOGIST instead of a regular gyn
jcdew, did you see a Urogynecologist for your second appt?
Also, did they tell you how they are going to ( and if they intend to ) suspend your vaginal cuff after hysterectomy in particular? If you dont get the top of your vaginal cuff suspended you could end up with further prolapses further on after your operation.
If you have your front and back wall operated on as well you could end up with some tightness vaginally but ask your surgeon about this and if you will be given womens physiotherapy after you have healed to help you with tightness as well as strength and further healing.
I am surprised your original gynae gave you a ring pessary when you also have a rectocele as they dont support rectoceles even if the ring pessary has a support in it. This could be why your prolapses progressed, although they can progress anyway and a ring pessary can be a good option for a uterine prolapse. It is tricky to get all of them supported well.
If you operation goes well you could have better sex as long as you sort any tightness out after you have fully healed.
I hope this was helpful and please ask further questions if you feel the need
You might find more luck on the hystersister site or patient.info