I just copied this from a website, some of the ideas may help you. You have to actually do them, though, dont just think about them… actually do them!
Cultivate self-appreciation
Write a list of your top seven qualities as these are what make you unique. Carry these around with you every day and read them to remind yourself of who you are and what makes you special.
Write a list of past successes
Think about the times in your life when you’ve been successful at something. Write a list of all of these and remind yourself of how you did this and how great it felt when you’d achieved your goals. Use these past experiences to fuel your self-belief and confidence for achieving your goals now.
Don’t engage in negative dialogue
Don?t put yourself down in front of others as it succeeds to tell you and everyone else that you don?t value yourself and have a low self-confidence. (Don’t post something like this again!)
Support yourself and put yourself first
Be your own best friend. Don?t beat yourself up and call yourself names. Be encouraging and congratulate yourself when you complete actions moving towards your healthier lifestyle goal. This will help your self-worth soar.
Choose positive role models
By looking at others in a constructive way rather than negatively comparing, we can help ourselves. Look at others with a glowing self-confidence and notice their characteristics. Pick up words and body language that they use and add this to your own repertoire.
Accept compliments
Being able to accept, believe and feel good about accepting compliments is crucial to cultivating a high self-confidence. The best way to accept compliments is to look the person in the face, smile and say thank you. This will in turn also make them feel good. Looking embarrassed, and feeling uncomfortable will also make them feel uncomfortable
Banish negative beliefs
What are your negative beliefs and how have your negative beliefs held you back so far? Cross them out and make a pact to add nothing else to the list.
Adjust your body language
Having good posture tells your mind, and others, that you?re looking good and feeling confident.
Use positive affirmations
Using positive affirmations everyday is effective as you?re communicating with the negative thoughts stored in your sub-conscious. Pick three strong statements, which literally make a negative self-belief into a positive one. For example, if you believe you?re not a confident person then ?I am a confident person? should be one of the positive affirmations that you say every day. Say your positive affirmations out loud while looking in the mirror and connect with yourself.
Redefine your self-image
Think about and write up who you are now. Identify the bits you want to change and rewrite a definition of your self-image. Read this everyday for the next three weeks at least and be that person. Prepare for the changes you are going to make and the new you by throwing out your old clothes and thinking about how best to dress your new self. Then go shopping!