Proton mail, need some clarification?

I recently created a proton mail account after downloading the app from the play store using a Gmail account. Was this a mistake? Also, when using proton mail through other apps downloaded from the play store, will I be indavertently sharing my data with google, defeating the purpose of my switch to proton? I like proton's interface better anyway, but if there's no advantage it might be better to have just two email addresses (Microsoft and Gmail)