Brief Answer:
Needs pain management and weight loss. Not autoimmune.

Detailed Answer:
Thank you for asking

I read your question and i understand your concern. DIgestive problems are likely a sequelae of medications and just need supportive care with antacids, prokinetics and diet and lifestyle modifications.

Pain in the knees and arthritis needs rheumatological evaluation to sort out the cause of arthritis whether its just age related articular degeneration also called osteoarthritis or some thing else. With obesity in history, osteoarthritis is the highly likely cause for the pain and needs NSAIDs and physiotherapy exercises to keep the range of mobility.

Just one abnormal swollen lymph node does not mean you have an autoimmune disorder. Swelling, inflammation of joint on its own give lymph node swelling. Also a simple cold and flu can cause lymphadenopathy. So wherever the node is, keep an eye on it, take some advil for that and wait for its resolution. Its neither autoimmune nor any thing grave.

Nutshell, pain management should be the priority and losing weight is the key. I hope it helps. Take good care of yourself and don't forget to close the discussion please.

Regards
Khan

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