Finished my brachytherapy for cervical cancer 1st of Aug. Want to go back to work but don't have the strength I used to. Is this normal?

Finished brachytherapy foe stage 3 cervical cancer on 1st Aug.  They have told me it will continue to work on for 3 months then I will be scanned .. I so want to go bk to work but also realise I don't have the strength I used to have.. is this the norm ??