kefir

I have just begun drinking kefir and am feeling some negative side effects. Im basically anxious, irritable and have insomnia. ive taken many Antibiotics over the years, as well as eating a lousy sugary diet, so its been advised to take a probiotic. Im only a day and a half into it, but my insomnia is really bothering me. What im wondering is, is this just a side effect from a die off/ healing or something else? If so is there anything i can do or take to help? Thank you Tweet