I think this suggests a false dichotomy, although I'm sure that's not what you meant to write.
Quick thought experiment: would you tell a physically abused child, to their face, "Do you honestly believe your misery is a result of external consequences? Be grateful for what you do have."
Some people habitually blame things that they caused themselves on others. Others commit the converse and blame things other people did on themselves. I don't think either of these facilitates your mental health.
If you are an adult, almost certainly things happened to you that weren't your fault, but that are your responsibility. That's life. Life is the process of dealing with those things, and then you die. It sucks, but it's worth it. Am I out of platitudes yet?
All these habits are founded on a desire to be better, which in turn needs to be rooted, at least partly, in compassion for yourself. If you don't want to be better, because you don't think you deserve it, because you have had that beaten into you, why would you exercise or eat better? And the only way you're guaranteed to have compassion for you when you need it is to learn how to generate it yourself. You're not going to exercise or eat clean or anything healthy sustainably if you're sustaining it by abusing yourself verbally or emotionally. So don't do that.