Both ankles sprain OFTEN!!

I’m 34 and for have been riding horses competitively for almost 15 years. For many years i’ve been stuck with these ankles that twist all the time, sometimes my ankle bone will actually hit the ground without causing me too much pain, but just as often i’m laid up from simply walking across the kitchen floor, one will often just “give out” on me. I spent two of my three pregnancies living in two(!) aircasts to avoid injuring myself too much. I’m fairly knock kneed and i’ve wondered if either that or the constant stretching of my tendons while riding (heels down) might be factors in this chronic problem. I also tend to have a very hard time walking in the morning, lots of stiffness with pain. I’ve been checked for arthritis and xrayed, a touch of bursitis in one foot or ankle(can’t remember which) but that was all the medical help i’ve been able to get despite many many visits and lots of whining. Any advice would be very much appreciated, my quality of life is suffering. I have three kids, two of them with special needs, and I just don’t have the room in my life to be in pain all the time. I just did it again this evening, bad fall in the house on a nice flat surface, agonizing pain and cramping in my foot and ankle but little swelling so seems fairly minor. As long as I hold it sensoreded in the direction I sprained it I can stand the discomfort. Of course I have no idea how i’m going to carry my 35 pound toddler down the stairs in the morning! lol Thanks for reading and any help you might be able to offer in advance.Melissa