I meant to ask also if you had any radiation? There is radiation induced necrosis that can cause pain & swelling, that may have been the other issue.
Either way, so glad you reached out to your oncologist to get on this sooner than later. I hope you are able to get answers & treatment quickly. I have not been diagnosed with lymphedema, but I have had swelling issues so I wear a compression sleeve & gauntlet on my hand every time I exercise & ride on an airplane as a preventative measure. Hopefully after you are over this bout of lymphedema the compression garments will keep it managed.