Start by relaxing. We all come with baggage and those of us who are truly obese often have more baggage than the rest.
Self-doubt, self-hatred, and just plain feelings of unworthiness are common feelings that we have to battle regularly. People argue that we have no self-control - which is NONSENSE in every sense of the word. It is not our self-control that is lacking, it is the love of ourselves and the respect for ourselves, and even the LIKING for ourselves that is missing. I read a great article that suggested that instead of trying to FIGHT these feelings head-on and trying to use brute force (what we usually do with starvation diets, crazy over-exercising programs, and various CRITERIA for success that NO HUMAN BEING could or SHOULD ever be expected to meet), that we should try tricking and outsmarting those feelings. Simply by using strategies and PLANS that make it easier to eat and exercise healthy than NOT to, redefine success as something realistic, to celebrate small successes, to learn to at least treat ourselves as we would treat a friend or a child who we cared about (I am NOT saying we have to LOVE ourselves, like ourselves, or even to respect ourselves at the beginning, BUT that we at least treat ourselves with some level of kindness, gentleness, and caring). We don't have to have the feelings to ACT in a reasonable and responsible manner toward ourselves. We don't have to have the feelings to behave in kindness. We do this for strangers and co-workers we don't love, and clerks in the store, etc. We don't normally beat up or yell at those people because they made a poor choice or made a mistake. Give ourselves at least THAT MUCH consideration.
Set goals that are realistic and reasonable - NO, NO, NO, NOT by setting a NUMBER goal, but goals like eating at least 3 servings of veggies a day, or doing 10 minutes a day of exercise, or eating a little bit less than yesterday/last week/last month/or even last year. THEN, when we DO succeed in achieving those small goals, CELEBRATE them. Use inspirational quotes, motivational messages, positive phrasing, and generally KIND, NICE, comments about ourselves. We don't have to say things like "I ONLY lost 1 pound this week" but rather phrase it in a positive way so we say "I LOST ONE WHOLE POUND this week, that reminds me that I CAN DO IT"