A COVID-19 infection can impair vital functioning, but the gravest risk is for your respiratory health. Lung capacity can be greatly reduced, and if you have battled a severe infection, it can take a long time to build capacity back. Hence, encountering frequent breathlessness, palpitations, chest pain, fatigue can be common. This being said, remember that your body will need time to get its strength back. So, firstly, do not exert yourself and slowly pace yourself back into work and a normal routine. Do not rush in, or perform tasks that will strain you.
You can also consider splitting tasks into smaller activities, and prioritize work in the part of the day when you have the most energy (if that is possible). Those on continued oxygen support should not stop it. Lung-strengthening exercises, breathing exercises and yoga asanas may also be tried. However, do only the exercises which are suitable, and not strain you.
Do remember that if an activity tends to make you breathless or tires you out, do not skip it completely. Instead, rest and try to be consistent. Be gradual, and slowly, you will be able to resume the normal pace of life and do chores faster.