Take a read of Tao Te Ching. It's written 2500 years ago about spirituality. Find a translation you like. Don't read explanations of the poems - It's designed for you to find the meaning yourself. Once you've gotten a meaning for each of the poems in relation to your life (Chinese philosophy is generally experiential rather than rational, subjective rather than objective), I'm hopeful it will help you get "there" wherever "there" is. I don't think it'd take you more than a few months to a year to get through the book.

So I'd go for "embark on a spiritual journey into your own mind".

My life is completely different than 4-5 years ago. Most of the acquaintances I knew then probably think I've gone nuts, (and IMO selfish to show them how good my life is now), but my best friendships have become even better; I really like where I am right now in my life - every day I wake up and enjoy it - At this point in my life I've spirituality, health, family, finance all sorted. I've met hundreds or thousands of people in my life, have not met anyone else who've got these four things together as well as has happened to me yet (except my wife) - and I don't know if it will last; but it all started when I started poring over those poems.

Anyway - most people these days tend towards an atheist/rationalist point of view and have no interest in books on spirituality & religion from 2000+ years ago, and if you did not ask the question I would not have written this comment. I do hope it helps you on your way.