Can i become re-infected once i've had a fungal infection?

Unfortunately, yes: Yes, it is possible. The skin infections often recur in the same patient. Athlete's foot, for example, is a common type of fungal infection that may occur many times in a patient's life. Other types of fungal infections can occur on multiple occasions as well. They are typically not like a stable virus or bacteria that one can receive a vaccine for. Fortunately most fungal infections are benign.

Yes: You do not state what type of fungal infection you're referring to but as a rule fungal infections do not induce long lived immunity to reinfection.