Hi Marcos.
the short answer is that you can- I did. A number of claims are made for creatine and I can't comment authoritatively on them, though I concluded that there was the possibility of some benefit, and little downside. My main objective was to slow the loss of muscle mass which goes with the reduction in testosterone caused by the hormone therapy.
Creatine in itself isn't a magic bullet. As I understand it, it works in the context of muscle repair so it needs to be seen as part of an exercise regime which pushes you hard enough to generate a bit of muscle rejuvenation. And actually it's the exercise regime which is probably the more important bit.
You are obviously in a lot of discomfort, so you will need to be careful in putting together a plan for yourself ( or even get some advice) , but plenty on here will attest to the value of keeping active with a mixture of simple cardio and resistance exercise.
Best of luck
Ron