Kickstarting a New Ketogenic Phase

Hello.
I'm a husband, a dad, and addicted to carbs.

A few years ago, I tried the ketogenic diet. In 4 months I lost almost 40 lbs.

Then, autumn hit, and my mom started baking, and my resolve was dissolved in a flurry of butter cookies. I told myself "We'll just do a modified keto diet, just a few carbs added back in for fun." That was 60 lbs ago.

Since then, I've had some drastic events happen in my life. I contracted meningeoencephalitis which hospitalized me for 9 days. It left me with PTSD and some other harder to define mental deficits. I also, in the course of figuring out how my brain had changed due to that sickness, learned that I am bipolar. Looking back into my past, I can see the peaks and valleys of my manic-depressive cycle,  and my illness triggered the disorder to get an order of magnitude worse.

I'm medicated now, using Seroquel each day, so the effects of my bipolar disorder are less drastic, but it's also not been helpful for my willpower, for whatever reason. I tried just dropping candy from my life, and made it 21 days before I had cake. Then I made it a further 20 days - I didn't lose any weight while off sugar, so I became very disillusioned with the process - before I just quit and went back to my old habits.

I'm currently on the upwards side of 285 lbs. This is the heaviest I've been in my life. I feel it, physically, every minute of the day.

I get winded just tying my shoes.
I can't play physical games with my kids because I get too tired, or my lumbar goes out of whack.
If the zombie apocalypse happens, I'm bait.

So, I'm researching, and I'm planning, two things I barely did last time. Lack of variety was my undoing last time, so I won't make that same mistake.

Something else I didn't do last time was secure the support of my family. I started a diet that wasn't suitable for my wife or kids. This time, I want to have family-friendly menu choices that only require minor adjustments for me, and are still yummy and nutritious for my kids.

After making some lists, some menu plans, and purchasing the right foods for our kitchen, it'll be off again, seeking ketosis.