Hi there benjy, welcome here to the forum and our online community.

Firstly, don't be concerned about the refusal of the Visitor Visa. That will have no impact whatsoever on the settlement visa.

What I would say is this, please do some research here on the differences between Fiance(e) visa and Spouse(Partner) visa.

Have you considered getting married in Philippines ?

I only say that because it's sometimes tricky to prove your intention to get married here in UK without secure evidence.

Take a look here, or search the forum about how self employed are best advised to present their case for the Financial Requirement evidence.