New symptoms and waiting for breast clinic appointment

Hi everyone I’m just after an opinion. Back in Jan I developed a small swelling under my left breast and intermittent sharp pains in the breast, by march it was still there so I saw my GP. She didn’t seem overly concerned but said it warranted a non urgent breast clinic referral. TBH I wasn’t convinced that was necessary but went with it. Appointment came through for August so I figured I’d keep it. Fast forward to late April and I developed a small red rash on upper right quarter of breast, over time it extended but no lump or anything. Over the same time period pain got more consistent. Gradually the rash got bigger but some days seemed brighter than others so still didn’t think much of it. Then over the last month the rash spread round the bottom and outside but still it varies day to day in how angry it looks. By now the pain is constant and it feels heavy and just kinda weird. I also have hard nodules on my collar bone the same side. Up until yesterday still no lump but today I can feel a distinct hard lump on the outside and at the right angle I’m pretty sure I can see it. Now I’m a bit freaked out. My question is my appointment is on August 16th so about 10 days away. Do you think it’s fine to just wait for that (apart from the anxiety might kill me!) or should I go back to the doctor before then? I’m not sure if it would make any difference at this stage? Thoughts? !thanks everyone, I don’t want to be dramatic but of course don’t want to delay stuff if there is something to worry about. I’m really unsure how to proceed.