Sorry you were treated so poorly. There are some very bad therapists out there. I've struggled with the notion of what I am responsible for with respect to my health throughout the last nine years of having moderate ME/CFS. (With some periods of mild I guess? I'm still hazy on the classification. I've been unable to work, read for long, study, etc., during this period, but I could go for a 15-20 minute walk every 3-7 days for many years.)
Since four GPs and an internist had nothing to offer me (including a diagnosis), I spent many years trying to find the most 'evidence-based' naturopaths / 'unorthodox' doctors to help me. I spent a lot of money on all kinds of supplements as part of various protocols that I scrupulously complied with. I followed an increasingly 'clean' and strict diet, and tried all kinds of diets that I was told could help (Wahls, bone broths, etc.)
I focused on doing everything that could even notionally improve my wellbeing: following as much of a daily routine as I could; doing mild stretches and a few core strength exercises; doing short meditations whenever possible; being mindful of 'ruminating' and unhooking from it as often as possible; going to sleep early and practicing good sleep hygiene; trying to establish an online peer support group for emotional support; etc.
And I felt guilty and complicit in my poor health whenever I deviated from perfect adherence to all the things that were supposed to improve my health. E.g., when I ended up smoking weed to alleviate the tedium and isolation, or when I didn't go to sleep early all the time, etc. Or when I used coffee and weed to play video games when the inactivity and 'cabin fever' drove me insane, followed by inevitable crashes.
I have still not been diagnosed with ME/CFS, although my current GP told me she would give me a diagnosis if I need to apply for disability benefits, which I will only be eligible for once I have exhausted all but $5k of my savings. Looking back, having a bunch of bullshit provisional diagnoses (chronic Lyme, etc.), and holding myself more 'responsible' for my health than I actually was, gave me a fake but not unhelpful sense of control. Ironically, it also gave me something to do - comply with useless 'protocols'.
There's an old saying that having the wrong map is better than having none, because at least it conveys a belief that you aren't completely lost, which is terrifying and debilitating. There are obviously costs to having the wrong map though - financial, emotional, existential, etc.
I've been trying to find a therapist for roughly a year, and it's been a slog. Many of them feel like they can help alleviate my ME/CFS symptoms in therapy, even though I'm just looking for support with an impossible situation. All that to say the question of what it means to 'take responsibility' for my health and wellbeing is very loaded in my experience.