Nonambulatory without device since unknown insect bite x 5 weeks.

[Miss_Will]

Five weeks ago I was gardening when I was bitten by an unknown insect on my right lateral ankle. I am a very active 66 year old that typically walks 3 miles a few times per week. Day two area was painful but I could walk. Day three area was painful and I started having difficulty walking. Day four area was red, swollen and with signs of cellulitis and I needed assistance to walk. I have since taken 4 rounds of antibiotics and 2 rounds of steroids. An ultrasound was negative for DVT and X-ray was negative for fracture. MRI reveals cellulitis, edema and possible myositis. This whole time the pain has been at the bite site and six inches up my leg. I have seen 2 family medicine MD's, an ER doc and sports medicine MD. I feel as if I am never going to walk again without a device and feel I am not getting any better. Docs so far seem at a loss of how to proceed. Has anyone seen these symptoms before or know what the diagnosis could be?