Instead of adding a huge undertaking onto your already heavy load, I recommend using a technique that will help you ease into a healthy lifestyle through steady and intentional habit changes.
Start by listing the top 10 habit changes you'd like to make. Choose the ones that will really improve your life. They can be subtractions or additions of habits. For example, you could give up smoking or begin to drink water or tea more.
Of those 10 habits, list them in order of easiest to hardest for you to commit to and start with the easiest habit first. If you practice that habit consistently for 2-3 weeks, add in another, and so on.
There are some instances where people really succeed in making drastic changes, but, honestly, it can work well... or it can crash and burn. I've seen both among my friends, clients, and even myself. Someone has the best intentions, but unfortunately it does not work out as planned. We all have bought supplements, workout videos, or gym memberships that weren't really used.
On the other hand, some people are gifted at stirring up enough enthusiasm in themselves to make big changes quickly. I've worked with some of these people in Uplift's 21 Day Challenge program. They wanted to lose 2-6% body fat in three weeks and would follow a holistic program for that time to make headway on their health goals. Though they achieved extraordinary results, it took effort and accountability on their part.
Either path you choose, if you can stay on track for a few months, you're in good shape to keep it up into the future.
Just remember that you are human and, just like everyone else, you mess up sometimes. When you break a good habit you've been working on, don't wallow in negative thought. That will only make the behavior spiral out of control.
Instead, give yourself the opportunity to prove what you're made of and get back on track. Your resiliency will improve with time as you become more accountable to your lifestyle.
Good luck and reach out to me if you have any questions!