Looseness after childbirth is the result of damage to the vaginal muscles and to the vaginal supports. These are the same muscles that you use for kegel exercises and also the outer muscles of the vaginal opening (the perineum). The vaginal supports are the same supports that hold up the bladder, the uterus and the posterior vaginal wall.
Your photos show significant damage to the muscles of the perineum. The distance from the anus to the vaginal opening is very short as a result of this damage and the vaginal opening is gaping because the muscle tissue in the center ripped apart at childbirth and is now displaced off the to the sides. An exam would be needed to assess the amount of damage present on the inside, but there is a suggestion that you have looseness in the posterior vaginal wall called a rectocele.
You would need, at minimum, pelvic floor reconstruction of the posterior vaginal wall and a vaginoplasty with full tightening of the muscles of the vaginal canal (levatorplasty) and total reconstruction of the perineum (perineoplasty). This is expert level work that I conduct on a regular basis.