and it's harmful to think that

If I may: my therapist says--and I'm beginning to agree with her on it--that thoughts themselves aren't inherently good or bad; it's what we do as a result of those thoughts--physically, verbally, etc.--that can be considered good or bad.

So, with that in mind, phrases like "you shouldn't think this/that way" (which the quoted bit above basically boils down to) are generally going to set my hackles up. I know you probably didn't intend to come off this way, but in the future I would suggest a better choice of words.