Building a carreer based on Envato Themeforest and Graphicriver: What are your experiencs and recommendations?

Hi fellas,

I am graphic designer intending to be full stack web developer with work experiences in top notch ad agencies in Turkey since 2005 and i am fed up with working with various clients and endless stress therefore i am thinking about to step into envato marketplaces to produce good quality works per month. I am no stranger to themeforest and for 2 years, i am thinking about to dive into themeforest but i hesiatate in same time. I am not sure if i work hard enough can i succeed to make enough of living to pay my rent in 1 month.

Here is my plan: Reviewing mechanism is hard and taking so long time and im thinking about 9 month plan to gracefully switch my way from freelancing to content producer.
first 3 months: i will be producing 1 muse template per week while i test 1 html template.
second 3 months: i will be uploading 1 wordpress plugin and 1 html template per month.
last 3 month: i will be producing 1 html, 1 wordpress theme and plugin per month and settle on more stable ways of make living.

I have cost of living mnimum 500 $ per month and i dont want to stress about about it. In which time, can i succeed that and how? Is envato trustable for generating passive income? What are you experiences? And what can you suggest me as recommendations?

Looking forward to hear your opinions.Thank you.