Keep trying to freelance. Don't give up. If you can write good ad copy, you can make good money freelancing. It takes a little while to get started, but if you network well you can start making a decent income in a few months. You won't get rich, but you'll stay busy and make contacts. I freelance in another industry, but I know that good freelance copywriters are highly valued.

Regarding happiness, I'll be blunt and say I was never truly happy until I met my wife and had kids. I did the global traveling thing for several years, and it was fun, but I was lacking fulfillment until I started a family. I know that's not for everyone, but some people really would benefit from starting a family. If you don't have a family, it's something to at least consider.