I highly recommend this book: The Willpower Instinct: How Self Control Works, Why It Matters, and What You Can Do by Kelly McGonigal, PhD
I have it as an audio book on Audible, and I am listening to it for a third time because it’s so helpful. Also have it on Kindle. Amazon sells the paperback for less than $10. The narrator on the Audible version is only so-so in my opinion, but the content is excellent so I don’t care.
For mindfulness I highly recommend this one: Radical Acceptance by Tara Brach. Also less than $10 for paperback on Amazon. There is a section that talks about mindless eating, and I think about it often.
It sounds like you are in a tough position, living in a house where you don’t have full control over what food is (or isn’t) purchased. I am lucky in that I live alone, so I simply do not buy things I know are going to challenge my willpower once I get them home. Being on Soylent has helped tremendously because I rarely have to even enter a grocery store anymore.
I am also lucky in that I can choose to not have a TV in my house. That doesn’t mean that I don’t get stuck in YouTube land once in a while on my computer, but at least I don’t feel quite as depressed after YouTube videos as I do after TV. I feel like TV promotes mindlessness so I do not miss it at all.
Something that might be helpful: ask your family to help you. If they know that this is very difficult for you, they might be wiling to check in with you (you tell them ahead of time what the best thing to say or ask is) if they happen to see you when you are most vulnerable (in front of the TV or fridge, etc). Of course the danger would be that you lay the entire burden of willpower on them, and then you have other people to “blame” for your mindlessness, so you would have to be careful to not let that happen.
Usually our friends and family want to see us happy, so if we can explain that they could help us make good choices, they are willing to do so.
PS I do not think you are going to find snacks with fewer calories than the things that have already been mentioned in this discussion so far.