Having a complex or a hang-up means having a feeling of inferiority, which causes passing or persistant unease. It's most often based on imaginary faults that you see when you compare yourself to icons of apparent perfection, on a physical, intellectual or social level.
More than anything else, hang-ups are negative judgments that you often attribute to other people. But charity begins at home, so start loving yourself!
To help you love yourself, read guidance from our psychiatrist and sexologist. It doesn't have to be that difficult to come to terms with yourself and value who you are.