Lost a stone and a half and now nothing fits properly

Been losing weight deliberately since January, about a stone and a half so far and still going. Everything about the fit has changed. The ring now moves in a way it did not, and twice this month the whole thing has shifted enough overnight that I have woken up uncomfortable.

Do I buy a new ring now or wait until I stop losing? Buying twice seems wasteful and wearing something that does not fit seems worse.