Your GP should be able to help. But please do some reading up as well.
Found these articles and wondering if they would help:
https://breastfeeding.support/how-to-stop-breastfeeding/
https://www.wslhd.health.nsw.gov.au/ArticleDocuments/1383/Medication%20to%20dry%20up%20your%20milk%20-%20lactation%20suppression%20V5%20FINAL%20April%202018.pdf.aspx