I too was having a difficult time with accessing this question - there must have been something wrong with the site for a while.
Assuming that you did not have a problem BEFORE the accident, and that the accident itself caused some kind of injury to the pelvic floor, then I would not rush into any kind of surgery without pursuing some kind of alternative options.
I will liken the 'injury' to a vaginal birth, with a significant amount of strain on the pelvic floor. You were likely prone to prolapse, likely related to prior childbirth.
Think about pelvic support in the following way:
1. There is support of the top of the vagina
2. There is support of the bladder wall of the vagina
3. There is support of the rectal wall of the vagina
4. There is support of the vaginal opening between the rectum and vagina
You are describing the common problem related to loss of #1 and #2. Any bulge or vaginal skin that you can see at the vaginal opening is likely related to the bladder wall. In your case, since things happened so suddenly, you might consider:
1. Pelvic floor rehab - intensive Kegel exercises with a Physical Therapist
2. Pessary - you can use this as needed and can be taken out whenever your want. You could consider it something you use when you are active or exercising, for example.
If all of this fails, I would not pursue an alternative surgery to the one you described. It is NOT the standard of care for surgical treatment of prolapse. Also consider that loss of sexual function is NOT usually a problem for women after surger for prolapse (i.e. the TVH/APR) that you described.
Again, I would recommend trying pelvic floor 'rehab' for at least 6 months before considering surgery. Also, don't rule out the use of a pessary - it is non-surgical, non-hormonal and harmless.
I hope that this helps - please ask me if you have any further questions.