Tough question, because SO much of my life went into suspended animation when I started developing GAD and MDD.
One thing for sure---I'd parcel up some money for friends who have been going without for far too long, and hopefully ease the stress they've been feeling.
I'd travel.
I'd also start a business (home-based), and get back to a few hobbies I had to abandon so long ago.
I would hook up with favourite charities and do as much work as I possibly could for them, AOAP----and also make a priority out of following, and perhaps contributing to, Mental Health Initiatives (and research) here, and in the States.