I Am Concerned That There May Be An Underlying Issue

I am concerned that there may be an underlying issue going on. For the past 5 weeks I have been plagued with continual infections. Started with Strep throat, then shingles, then a sinus infection, which lead to a yeast infection (from the antibiotic) was given a prescription for that, which after 4 days I still have, and now I have pink eye, which I have drops for. I have been taking probiotics, eating yogurt, vitamins, orange juice, ect to try to boost my immune system but I am worried.