I'm sorry, I don't think there's any treatment that can restore pain sensations that have been lost.
If the loss of pain perception is temporary, as a result of a relapse, then a course of steroids might restore it quicker.
But if the loss is permanent, you have no choice but to be very, very careful how you go about your daily life, and always check for signs of any unnoticed injury.
I only have very slight experience of this, and fortunately I did not break any bones, or cause myself other serious injury, at the time. But I did go through a phase of having absolutely no sensation in my feet, including pain.
Although I didn't put it to the test (probably not a good idea), I was convinced I could have trodden on a drawing-pin without feeling it. And I had to be very careful getting into the bath, in case the water was too hot, and I couldn't tell.
It might be possible to do something about why you are falling - e.g. is it a strength or balance issue? Do you need a mobility aid (or different one, if you already have one)? If your bones are breaking easily, when they really shouldn't (e.g. osteoporosis), it might be possible to treat that, too. But I don't think the issue of not feeling pain is one that is treatable. If pain signals can't get through, it is because of damage blocking their path. Unless that damage repairs by itself, or with the help of steroids, the pain signals still won't be able to get through. There isn't a pill you can take, that will let them leapfrog over the damage.
If there was, MS wouldn't be a problem, for anyone.