Anxiety

Is there any reason why my anxiety has been fluctuating so much?? I have found in last few months or so I haven’t felt even remotely like myself which is odd because I’m typically a very happy person that is always laughing that try’s to stay positive for other people and myself. I don’t know what has happened. I don’t eat the best or much at all because I have IBS so I’m always worried about what I eat sending me to the bathroom. Idk if maybe it’s because my life has changed so much and I’m not used to it or what! Could it be my diet? Does anyone know anything about supplements or diet or certain deficiencies causing anxiety?? Please help I’m just at a loss and I want to get myself back.