Shampoo isn't really going to do much, as it is a rinse off product. Plus it doesn't do anything to address the issues causing the loss in the first place. A big problem with both Lupus and the meds used to treat it is that they prevent the body from producing enough collagen, so you really need a good collagen supplement.
I take this one and have seen new hair growth since starting it despite the meds I am on: NeoCell Super Collagen + C – 6,000mg Collagen Types 1 & 3 Plus Vitamin C - 250 Tablets https://www.amazon.com/dp/B00028NGEC/ref=cm_sw_r_cp_apa_i_wu6mCbMHJ102Q
Castor oil applied to the scalp has also been shown to stimulate growth. I use a syringe rather than a dropper (because it can hold more) to apply it to my scalp and rub it in, pretty much coating my entire scalp in it. Then I leave it on for a few hours (or even overnight) and wash my hair.
Because of the lack of collagen and the meds you are on, your hair is likely very prone to breakage. So you want to take the steps you can to prevent it. Get a silk pillowcase. It will reduce breakage while you sleep. Also be very gentle when you brush and use a good conditioner after you wash (I love Redken All Soft, but you want to get something that works with your hair type). A lightweight leave in oil or multi-purpose styling product will also help. Get one designed to prevent breakage. You may also want to try a few keratin mask treatments to strengthen your hair (you can buy ones that you can do at home; they are usually pretty inexpensive).
As for making your hair look thicker while you wait for new growth, start with a hair cut. There are certain styles that can make hair look thicker than it is. Find a good salon and a stylist who will work with you to find a cut that makes your hair look thicker (it will depend a lot on your hair type and texture). There are also products that can make your hair look thicker. Several brands sell texturizing sprays and powders that basically grab onto hair strands and double their size. I use one by Big Sexy Hair, but there are so many different kinds. If you have an Ulta store near you, I would go there and ask someone in the salon area to help you find some products that will work for your hair type.
I hope that this makes sense and can help you a bit. I am on mobile, so it is kind of hard to format things.
I take:
https://www.amazon.com/gp/product/B00028NGEC/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0094IUIKQ/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0094IUIKQ/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0017JIH7G/ref=oh_aui_search_detailpage?ie=UTF8&psc=1