Can any experienced JW advise me?
First, why on Earth are you asking for advise from a JW here in an ex-JW forum? Since you asked anyway, my advise is this: If you don't believe in the WT and the JW teachings, that's perfectly fine (trust me, I don't either). However, that doesn't give you the right to be disrespectful to the JWs who do. Partaking knowing what that means to them in that setting is disrespectful, regardless of what your belief is. And this is coming from someone who has no respect for the WT (just look at my posts and replies).
- You are not going to make your situation with your family any better (that is considering what you say that you keep putting up with the JW nonsense because of your family)
- You are not going to make a point to anyone, regardless of how correct you feel you are in your actions.
- All you will get (at best) will be 5 minutes of fame and in a bad way
- If you really want to manifest your faith, you don't need to disrespect other people's, especially that of your loved ones.
I'd suggest you to look into (a) why do you want to do that, and (b) why do you want to do that that way. The way you come across to me sounds more like attention seeking than wanting to express your faith.
There are many other places and opportunities for you to partake and do whatever ritual you want to do on your own, so neither it make sense for you to do that based on your own words about being there for your family, nor it will result in anything that will make your life better, not to mention that you will not make a dent in making anyone there believe anything you do. I do not see any point in doing that.