lady my girl dosen't have your problem and this may not help you. But it is a suggestion that you could try She her problem is she is very sallow and if i would penatre her fully she would have excurating pain. I could only enter her paratlly. So I came up with a idea to help her too take more than 4". What we did was go out and buy several size of anal plug and slowly started too strecth her. we buoght different length and with. we start out with a very small plug about 3 inches in lenght and about 1 inch thick we/she is now she is up too a 2 1/8 by 7 inch long plug with now pain now and she can keep it in herself up too 2 hours and having wonderful orgams now with no problems. This is just a thought and something you can think about.
But first i would try and see a therapsy and talk with them for some help also they may have some better ideas.

MrDom