1 month with symptoms and still no ultrasound

Hi, I'm just needing some advice from some people whom maybe have experienced what I'm going through so here the sitch...

woke up 1 morning in January and noticed a strange rash on my right breast red enflamed and hot. I'm prone to skin irritations with allergies that I have, so I didn't think much of it and put some otc creme on it. 1 wk later not any better and now a new rash on my left breast with same look and symptoms. Decided a trip to my dermatologist was wise. Diagnosed with Cellulitis given antibiotic and scrip topical creme. 3 days with topical creme redness decreased but still with rash for both breasts. Continued antibiotic for 10 days total with no improvement. I'm now 2.5 wks in with my breasts swelling and rashes spreading on both. Visit my GP after exam states he thinks its mastitis, but in same sentence admits he does not know what it is... decides to put me on second antibiotic and take me off of the other and a diuretic ne had me on for other health issues, stating it might be that as well?? It has been 1 month this past Friday and I have no improvement with 2 antibiotics and topical creme. The redness has now turned light tan and hardened the skin on both breasts, my breasts continue to swell and some lymph nodes in my armpits on both sides as well. I have a burning sensation in both breasts that will randomly happen and the rash persists with spread to my lower breast on my right side and my upper breast on my left side. Im irritated and dont know what to do or where to go from here.

Also, have you checked back in with the dermatologist? I think that would be my first call. What they prescribed DID NOT work, at least not yet. They need to know that.

Thank you all, the fact that Im in my late 40's and am through menopause and never have had any other issues with my breasts is whats concerning to me. I did follow up with my dermatologist 1 week after the 1st appointment and was referred to see my GP for further assessment. That is where I am now. Finishing a 2nd antibiotic that is not working....I feel as though I'm going in circles? Talked with my husband and we agree that Monday Im going to call my gynecologist and ask to be seen asap. I will update as soon as I have any new information. Thank you for the advice I truly appreciate it!

I have an update, I saw my ob today she did an exam and scheduled me for a bilateral diagnostic Mammogram tomorrow. She stated if the findings are negative on the mammogram she wants to move forward with skin/tissue biopsies on both breasts. I'm scared but relieved at the same time to have action being taken.