Hi @lilcuti, I would like to add my welcome to Connect along with @gingerw. You might also be interested in another discussion on Connect where other members share your symptoms and learn what has helped them.
You mentioned your legs and ankles being swollen. I also have lymphedema in my legs and wear compression socks which help with the swelling during the day. I found an article I thought you might find interesting and could possibly discuss with your doctor — Compression stockings as an effective treatment for erythema nodosum: Case series: https://www.sciencedirect.com/science/article/pii/S2352647517300643
I think a doctor that specializes in diagnosing and treating Erythema Nodosum is a rheumatologist or dermatologist but I'm not sure. As @gingerw mentioned, Mayo Clinic or a large teaching hospital would be an excellent choice if it's a possibility.