Am I sinful if I do not fast Ramadan this year due to a bone marrow transplant and follow-up with the doctor, and will my other acts of worship be accepted, and will I be rewarded for my illness?

If fasting does not cause harm or difficulty, then fasting is obligatory, and only qada' (making up the missed fasts) is required if one breaks the fast. If fasting causes difficulty but not harm, then fasting is disliked, and breaking the fast is legislated, along with qada'. If fasting causes harm, then fasting is forbidden, and breaking the fast and qada' are obligatory. If the difficulty or harm is continuous, qada' is not obligatory; instead, feeding a poor person for each day is required. As for other acts of worship, as long as their pillars and conditions are met, it is hoped that they will be accepted, and the ill person will be rewarded.