Welcome to our family! I am sorry to hear that you are feeling so badly and that you've had to be taken off of work due to this.
You did not mention if you were taking any medication. If you are, what meds are they? Often, with proper treatment, your symptoms can be alleviated to enough of an extent where you can return to work. Also, it might be a good idea for you to consider asking your job for a different type of assignment that would not be so taxing on you and/or for some type of job accommodation. Many members have found other means of employment that were a bit more conducive to the needs of their health.
In short, there is no way for anyone to say how long your symptoms will last. Lupus affects each us of differently and causes different limitations in each of us. How your Lupus affects you is a completely unique symptomology and your treatment options, management strategies, and lifestyle changes will also be completely unique to you.
Even though we are unable to answer your specific question, we are here to help you as much as we can and to answer those questions that we can. I wish you the very best.
Peace and Blessings
Look For The Good and Praise It!