i agree with amity, you need to put forth the effort for spells to work. you could try a confidence spell or a glamour spell, but again, it will only help so much if you don't put forth the effoty. cast a glamour spell, then the next day ask if you could join some people at lunch. small things like that.
maybe a crystal could help, bring a quartz with you for luck or something, when you feel nervous, hold the quartz and say something to draw strength.