It all depends on your feeling of “doing”.
If you think that all of your actions and reactions (or the lack of those) are fully yours, if you try to own all of them, make yourself the source, then you create a lot to answer for. Especially if you think they all happened out of your own free will and with an understood intention. Because many of our actions turn out differently than intended (life is free and forms itself due too an infinite causal stream), and we only understand very little of what is actually happening, there will be a lot of occasions to feel guilty or even ashamed for. Living like this is more or less equivalent with setting yourself up for disappointment, guilt and shame. There is no way to think yourself out of a such a system. The disappointments will grow into guilt and the guilt will accumulate into shame. It is only a question of time.
The other approach would be to acknowledge that life is free indeed, that everything happens because of an infinite and mostly unknown and unknowable stream of causation (in many religions personified in a God-figure), and that our own “doing” as the last shackle of the chain is infinitely small and relatively insignificant. Especially if you replace the concept of free will for that of conditioned reflex, there is actually not much to answer for or worry about. In that system of dealing with reality as it is, all is just happening with and around us and we are happening ourselves as well. It is totally free and nothing is innately right or wrong, it is just what happens naturally.
In contemporary society, especially since the so called “enlightenment” (which only brought another shade of darkness) and the French revolution, the first model has become more and more prominent, while in earlier times and among natives the latter model was prevailing. This is because natives have a deep understanding of the power and overall causal effect of nature, while contemporary people think that they are superior and nature is something to be manipulated, conquered and sidelined. This hubris not only is an illusion, we have to pay dearly for it, and one of the currencies is frustration, guilt and shame.
We used to be able to avoid, diminish or get rid of personal guilt partly by living according to religious rules, and asking for forgiveness to whatever god-figure we believed in when we messed up, starting with a clean slate whenever we wanted. But modern times have taken these beliefs and rituals away as well in most cases, and we are made to believe in a makeable world where we are personally responsible for everything that goes wrong, with or without our real influence. This is not true, and also much more than many of us can cope with.
So, look at your believe systems and ask yourself if your beliefs really hold truth? When things don’t go according to plan or wish, look at the whole causation, not only at the last little doings of your mind and body. Perhaps you will find some leniency. If you don’t like that word, you can call it realism. After all, how small we all are. A little compassion goes a long way.
This also applies to the first part of your question, where you ask yourself: “what should I do?” to speed up your physical recovery. Your choice seems to hover between only two intended results: improve muscle strength by exercise or allow healing by rest. Also here the answer would be: neither. Don’t focus on doing and abandon every thought of achieving some sort of result. People generally over-estimate the influence they have on about anything. But truth is, you don’t have a clue what to aim for, what is good for you in the broader view of things or how to achieve it. Just accept what is now and act well within the boundaries of the current possibilities of your body.
Perhaps as a dancer you were used and attached to telling your body what to do, possibly to compensate for cf telling your body and you what to do. But now (again) your body knows best and you have to accept that your body tells you what to do. In fact, this is the natural situation. There is nothing wrong with it.
As soon as you abandon both these goals, freedom arises. The freedom of all possible things that could happen, not limited to just these two results your mind could come up with. Why do you think your mind (or that of your doctors) knows what your body needs? It doesn’t. It only has a little knowledge. Your body has all the wisdom. It knows about muscle strength, healing and a million more things you nor anyone else could come up with. Don’t bother it with thoughts.
So, don’t think about goals to achieve, let your body call the shots and listen to it. Injuries like these can only heal in function and with a lot of time. That is, you gently try to do the normal things that present themselves and see what the response of your body is. Do what works and don’t what doesn’t. Any thought of some fixed end-result should be far from your mind. Be patient and let time do its thing. The more you push, the worse it goes. Muscle strength and healing and the other million things will occur together, each in their own pace, and when your body is ready for it, not when you are ready. You don’t know nature’s agenda. Try not to control this, let it happen. Surrender. Contrary to our conditioned believes, surrender will give the best results in the easiest way and the shortest time. Anything you do from the goals of your mind, will impede on the natural process. If you surrender and let go, you will give the best support to this. And nothing to feel guilty about as well. Win-win.
The first step (letting go/surrender) is the most difficult. After that, all will go by itself.