Ever wondered HOW you got manipulated? How you ended up in a trap where you feel that nothing you do is quite good enough, that somehow YOU are not good enough, that your partner seems permanently disappointed in what you do and even who you are? Here is the good news: the chances are that you aren't inadequate - you just got manipulated.
I figured something out a little while back - think carefully about your long term relationships. Not necessarily the one you are in, perhaps one in the past where it broke up with you feeling like crap and with the other party somehow always with the psychological advantage.
I would postulate that most people are of good intent: they mean no harm to others and often strive to help those about them. How do such people become manipulated?
Its horribly easy. Someone in a place of trust becomes critical of them, tells them they are not doing the right thing when what the criticiser means is simply that they are not doing what THAT person wants or even just not doing something the way that they want it done.
The victim acquiesces: a loved one needs something; plans are changed, compliance takes place. The perpetrator gets most of what they want, the victim is ever so slightly reduced in the eyes of both the perpetrator and themselves.
Time rolls on, years often. The cycle continues. Its a steady and slow rate of damage but very very certain. Eventually the victim will feel that there is nothing that they can do that is right, that their best endeavours are inadequate and that they are a complete failure.
The answer to the question "How do you control someone of good intent?" is easy; just keep telling them they are sinners, inadequate, not trying etc etc. It is a self fulfilling prophecy. They will attempt to improve when it is not improvement that is the aim but the satisfaction of someone else's will and intent.
So when someone suggests that you do something different from the way you do it or do something you weren't going to do and sounds critical of you in the same breath, just say "No thanks" and smile sweetly.
Where it goes after that is up to them. Don't get angry either - the chances are that the perpetrator didn't understand the impact - they were just following a proven "success" strategy for getting their own way.