One of the most frustrating things about this disease is the fact that it is not the same for everyone and that it follows no predictable path and has no predictable pattern. Just as the disease and its symptoms are different for everyone, so is the pattern of relapse and remission.
There is no way, at all, to know how long a flare up will last, if we will achieve remission, or how long remission will last. Each of these issues are individual and depend entirely upon the progression of your particular case. I am sorry that there are no concrete answers to give you.
What you describe is familiar to many of us and I think that we've all felt what you are feeling at one time or another during our disease. The painful joints are due to inflammation because your disease is active right now. The muscle pain/weakness that you describe can also be due to inflammation caused by the disease and is known as myositis. Also, many of us with Lupus also suffer from a condition known as Fibromyalgia. This condition causes persistent pain in most or all of the muscles in our body.
Unfortunately, we too often have to listen to the words for people who know nothing about our disease, how it affects us, and what we have to live with. Their thoughtless words are often not meant to be unkind, but they have the same affect upon us as if they were trying to be intentionally cruel. Sometimes, in response, we have to be equally thoughtless of their feelings and simply tell them that, since they know nothing about Lupus that they should keep their comments, opinions, and unfair observations to themselves. If they cannot offer you support, comfort, and understanding, then you prefer that they shut up and stay away from you!! If they wish to provide you with support, comfort, and understanding, then you will be happy to give them information about the disease to educate them and explain to them how this disease affects you!! If they are not willing to learn..then they are not good for you and you may have to let them go.
This is a very real disease with symptoms that can be debilitating, do not let them or their words minimize what you are dealing with. Please know that we understand, we care, and we are here for you.
Peace and Blessings
Look For The Good and Praise It!