A self-assessment can be reduced to Rationality and Support.
Rationality
Take a snap shot of your life today. The great thing about pictures is that they don't lie. A snap shot (food/weight log) will tell you how much you weigh today, not what you weighed last month or last year, or what you should weigh next week. I've been told, "I don't know how much I weigh because I'm too embarrassed to step on a scale, but I want to loose 30 lbs."
A snap shot (log/drug tests) will tell you how much you are drinking or drugging today. It will identify the triggers, drug of choice, amount, and consequences. I've had people tell me, " I want to stop my $1000 a week cocaine habit, but I can't afford to pay a professional to help me."
A snap shot will tell you what type of partner will work for you today; same sex, opposite sex, older, younger, race, or financial status. It will also tell you how much time you have today to dedicate to a relationship. I've been told, "I don't have time to complete a dating website profile or look at it daily and respond to my posts, but if I had a partner, I would give him all the time he wanted."
Support
What resources do you have to help you reach your goal? Can you pay for professionals to coach you along the way? Do you have an exercise partner, can you afford a gym membership, or weight watchers? Do you have friends and family that will support your change or are they afraid of your change? Would your family support a change in their diet? Are your friends current addicts? Do you live where you use? Can you move? Do you have resources and activities to replace times when you use. Are your friends single and therefore want you to stay single? Can you afford to date; dinner, drinks, movies?
Being realistic about where you are today and having economic and emotional support identified before you set out on your journey to change may make the difference between succeeding or failing this time around.