Auto-Immune and Lung Nodes? HELP PLEASE!

Hello,

I'm a 21 year old writing not about myself but about my moms current condition. Since our GP is very vague with information/answers and I'm extremely worried I thought I'd come on here looking for answers. My mom is 52, and within the last 5 years I've seen her health go down immensely. It began about 5 years ago and started out as a terrible bout of vertigo lasting about 6 months. CT scan of her brain came out clear. Then about a month after vertigo faded out (Serc helped) she woke up in screaming from a stabbing chest pain. The doctors ruled out a heart attack but because my mom had a cyserian from her first pregnancy (my older brother) they questioned if it was a gall bladder attack. She was sent for an ultra-sound and that came out negative. Then after about a week after that incident she woke up and couldn't move. Her shoulders, neck, wrists, fingers, toes, feet, ankles, calves, and even nose had swelled dramatically. Going to the E.R the doctors gave her a pure shot of a steroid anti-inflammatory in her hip and it worked instantly and she was told she had to see a specialist (Two doctors one specializing in rheumatoid and another in auto immune disease). Her blood work came in and was inconclusive to point to a specific auto-immune disorder, However her B12 and Iron were low. They put her on Celebrex, Hydroxiquine, Prednisone (5 mg), Actonel and a water pill to get down her high blood pressure (I forgot the name though). Blood work also indicated that rheumatoid arthritis came back negative but Ostio was positive in all the places she had swelled. Also I should mention if it's relevant or not that the bone in her foot has popped up (kind of egg like) in both feet and has never gone down as a result from the attack. The doctors concluded that she had an auto-immune disease, they didn't know what kind, they suspect connective tissue or another form of lupus but left it at that and never had follow ups.

About one year and a half ago my mom, feeling better, stopped taking the medications she was prescribed and just stuck to taking only Actonel once a week. Now however she got attacked again but sort of differently.
It began as chest discomfort , slight swelling of her calves and fingers, and feeling of malaise.
Thinking it was an infection she went to the doctor who prescribed Biaxin and also wanted a chest X-ray just for certainty that it wasn't pneumonia. The X-ray showed enlarged lymph nodes and a black spot. However that's all we know we don't know the size or where they are located. The Biaxin she took helped but the condition got worse.
She has said that it's only SLIGHT discomfort. Asked on a pain scale 1 being nothing 10 being pain she rated it a 3-4.  She has no, if any cough and the rare times she does cough she spits up white phlegm either liquid spit, or thick. Also she has a fever, a noticeable heat from underneath her breast (like her chest had a bad fever) and the feeling of malaise has grown worse. She describes the feeling in her lungs as a small slight pinch, an electrical prickle, and sometimes a very slight heaviness. She also had difficulty sleeping and her blood work came back again low b12 and iron and she has again high blood pressure (195/80). The doctor did order a follow up CT scan and my mom went to see her again and was prescribed an antibiotic Sulfatrim  (800mg/160mg) twice a day and also Prednisone (5 mg) 100 tabs. The Sulfatrim she had to stop because she had a severe reaction which is besides the point but the Prednisone is really getting her back  on her feet and she is feeling much better with the Prednisone and Tylenol combination and is finally sleeping 8-10 hrs a night. Other symptoms my mom has been experiencing with this bout is: Double vision, night sweats, and red sores on her upper lip that AREN'T cold sores and only go away with prescription Corticosteriod topical cream or ointment.

Now sorry for the rambling but I'm really really worried it might be cancer..though I've researched my butt off and cancer comes back with the same symptoms, smokers cough, blood in spit, chest PAIN etc. Can a doctor on this site give any clarity with what this could be?

I should also mention if a doctor or health care professional is viewing this that my mom has had infections with major organs. Such as: Kidney failure (from a bad infection as a child), Severe whooping cough (even though she was given the booster shot for it), Liver complications (First pregnancy was severe toxemia leading to eclampsia).
I don't know why I put those I just maybe think it could be relevant in anyway to an auto-immune set up. But I'm not sure.

Please someone help, it would mean everything to me.

Regards and God bless--Kristen