@Lynn65, my treated breast was warmer than the other for about 2 years after radiotherapy finished. If I overheat, it's still warmer than the other, another year on. You can have some swelling in the breast for months after radiotherapy, so it may settle over time. Have you checked out the Australian Lymphology Association website? They have some information on the site. You can also check to see if the lymphoedema therapist that you saw has recognized qualifications.
There are some options around to assist with breast oedema, but I wouldnt recommend spending a lot at this point
Take care