It sounds like you may have ankylosing spondylitis given that you are Hla b27 positive and you have pulmonary fibrosis. I believe remicade is a treatment for that, as is humira and cimzia. I'm not sure that cimzia caused your pulmonary fibrosis, it could be something that was caused by severe ankylosing spondylitis.
It does sound like methotrexate is out because of the lung fibrosis - from what I read, it could make it worse. So,it sounds like right now, your options are steroids and steroids.
There are 2 drugs in the crohns pipeline that may benefit you - please talk to your doctors about them to see if it will be safe for you to try. One is Stellara - it was recently approved for ulcerative colitis and there are clinical trials for crohns going on right now. A friend of mine was prescribed Stellara for crohns because she failed everything else, and she's in remission now. The second med is vedolizumab - this is in the process of getting FDA approval, but there are clinical trials ongoing that you maybe able to sign up for. I've heard lots of good things about this drug.
Both these meds are ot TNF antagonists and maybe safe to take even if you have lupus. But I'm not a doctor, you'll have to check with them to make sure, and they'll have to fight to get you into a trial or for insurance to pay for it.
Start with prednisone to get some quality of life back while you look into these options. Hang in there, there are options, and hopefully you'll find a way out of this soon.
Husband with Crohn's
Meds: Canasa (1gm), Lialda (4.8 gms), Remicade (10mg/kg every 8 weeks)
Supplements: VSL3 (2 packets), florastor (4 caps), bee propolis and lots of Greek yogurt
Currently In Remission