I know that it can be so very difficult to find that balance between work, family and self-care. It may seem that you are being selfish to a certain extent if you take time for yourself. However, you said that you goal was to be around for your son in the long run. If you committed to 6 months to 1 year of dedicating to your health (emotional & physical), that is a small sacrifice in his life that could mean being alive to you, right? I am almost positive that if you presented this to your wife in this way, then she would understand why you need the time to dedicate to your health.
I am going to post some information for you about self-care assessment and planning. Let's find a way to put this into your life.
Self-care assessment
https://www.ecu.edu/cs-dhs/rehb/upload/Wellness_Assessment.pdf
Self-care planner
http://socialwork.buffalo.edu/content/dam/socialwork/home/self-care-kit/my-maintenance-self-care-worksheet.pdf
I wanted to recap our discussion the other day. I am sorry for the delay on getting this to you. We talked about having a planner for you to schedule your breaks to eat snacks away from your work area. You want to begin a new habit and force this change in behavior for yourself. The goal is complete "abstinence" from snacks or food at your computer/desk. Here is the excel spreadsheet that I told you about that I am using personally. I did modify it to account for eating for you. You can continue to modify this as you need. The main thing is to use it as a tracker to see what is going on visually for yourself.
https://www.dropbox.com/s/y7gh6jihbml3jyj/WEELKY%20PLANNER_ADDICTION.xls?dl=0
Here is the original planner for self-care that I modified this spreadsheet from. You can get an idea of how this may work for you with positive affirmation, etc.
http://kriscarr.com/wp-content/uploads/SelfCarePlanner.pdf
I will give you a list of positive affirmations that you can choose from for your daily meditative thoughts.
Just some examples:
I choose to change my eating habits and I successfully do so.
I ignore false messages of hunger and eat only when necessary.
I forgive myself for eating the wrong foods and I transcend all feelings of unworthiness.
I love life and I am immune to the temptation of eating processed foods.
I easily replace foods containing refined sugar with natural foods.
Eating right is easy and fun for me. I love my body and take good care of it by eating correctly.
I successfully release the desire to eat beyond the point of being full.
I release the need for foods that cause indigestion and discomfort.
I substitute high fat foods with high water content foods.
I exchange high fat foods for high energy foods and all excess fat is now being removed from me.
For me, eating and emotional comfort are separate and I forgive myself for overeating.
I let go of all reasons and excuses for not eating healthy meals.
I replace dieting with healthy eating principles and habits.
Healthy eating and I are one and I am richly rewarded for my healthy eating habits.
I accept healthy eating as a way of life.
I only eat the foods that are good for me.
I eat the right foods at the right times.
I refuse to let other people influence me to eat too much.
I am allowed to decline food and do so in total peace.
I willingly keep my meal portions small.
I choose fruits and vegetables over salty, sugary high fat foods every time.
I get all the vitamins and nutrients I need.