I was diagnosed at 21 with mixed connective-tissue disease, subsequently re-diagnosed as Systemic Lupus Erythematosus a few years later, with symptoms of Sjögren's syndrome added in latterly -- just for fun.
I was really lucky in getting a quick diagnosis, as my GP was brilliant and recognised my weird symptoms of exhaustion, incredible weakness, and joint pain, along with Raynauds syndrome, as an autoimmune condition. I was a student at Oxford at the time, and I ended up with one of the leading professors of rheumatology in the country as my consultant, which obviously helped massively. I think having healthcare professionals who really understand autoimmunity is a huge benefit, and if you can find a suitable specialist to advise on the right way to look after your discoid lupus, OP, I think that will be the way to go.
My disease was very active and quite debilitating in my early 20s. I was on hydroxychloroquine sulphate (Plaquenil), which is probably the antimalarial that was mentioned to you, and lots of different NSAIDS to control the joint pain. The Plaquenil worked really well to address the general feeling of exhaustion/ weakness. In my later 20s, and for most of my 30s, I was pretty symptom-free, with a few bad flare-ups and weird systemic inflammatory events along the way. I'm grateful I've not had to take steroids so far, but I wouldn't rule it out in the future if the disease became very active again. I'm now 42...