It is sad for you to have been experiencing this over the years. Manipulators are inevitable in love relationship but there ways to ways to defeat or silent them In a relationship with opposite sex. Here are few tips below:
It is very important for you to study your partner's weakness, likes , dislikes, level of understanding and reservation, these features will enable you to adjust yourself in such a position that the trust and respect which is basis of every relationship especially with opposite sex will be established between you and your partner.
Love language understanding and compatibility must also be understood. Aside and trust and respect, you also need to know the love language of your partner, for instance if your partner loves going to watch movies in cinema, it is your duty to try as much as possible to grant her that when ever it is needed, gifts are also areas you need to work on.