I actually give up, please help?!?

i never seem good enough for anyone anymore, reclenty i got talking to an old friend over msn, we met up and now he hasnt even spoke to me since :/ i think its because of my confidence levels, i just feel like crawling up into a ball most recently, since ive lost my best friends im not the same person, can anyone give me advice to boost my self esteem and confidence? xx