i just heard on a tape, that if one is not sure if they’re doing something for the right reason or for the wrong reason, they should do it anyways, but try to work on themselves for doing it for the right reason. it is the yetzer horah which tells them not to do so.
but, i’ve also seen something else happen. sometimes people try to do chessed for someone else, but it’s really too much for them: meaning, chessed that only they can do for their own family (like supper or laundry) is not done or mother is overly stressed cuz took on added thing which really did not have time for, so starts yelling.
however, if case is when person could really do the chessed but just don’t want to be a pushover, can choose to do it anyways. if they think it’s creating an unhealthy environment for themselves and are really furious about doing it, my own opinion is that maybe they shouldn’t or maybe they can find another more healthy way of helping the other person.
there are many disorders that are caused by the mind/body relationship and repressed rage because trying to do good even when don’t really want to is often the cause.