I have breast implants and have been told I have periductal mastitis.

If you have an infection associated with your implant that is not improving on antibiotics, then usually implant removal without replacement is required. Because it can take 6 months for it to be safe to be replaced, many women opt to remove the unaffected one so that they have relative symmetry for the 6 months it is out. That decision would be up to you. With the implant out, the cosmetics won't be optimal, but recontouring with breast lift or implant replacement will need to wait until the infection is clear and the tissues are soft and supple which can take a full 6 months.