Your health comes first. Aim towards recovery and getting yourself right. plenty of time for work and the stress it brings. You currently don't need to be stressing. Get some exercise if you need it, but don't over do it. Allow your body time to heal, we all are different and what works for one may not work for you. Listen to your body and do as much or little as needed.
Work will have to understand, no point going back and then going out sick after a day. They say time heals all wounds, we'd just like it to be now. Take care.