I have quit caffeine a couple of times. I’m such a fiend for it but it definitely increases my anxiety and makes my sleep less regular too. I taper off because I drink astronomical amounts. I usually halve my intake week over week until im down to just a cup of tea or something light, at which point I start taking odd days off of caffeine and then none at all. Normally my caffeine free streaks last a couple of months, until some late night project or early morning meeting ruins my energy levels and I start the cycle all over again.