Talk to Sexologist on Varicocele

Hi i want to ask the solution about my problem vercocele. I don't usually face this but sometime when i had my erection again and again and sometime i wear different underwear this happens, but after sometime if i lay and rest it goes automatically help recovers fast if i remove underwear too. WHen it comes its painful sometimes it comes on left testis sometimes on right and sometimes on both. Kindly tell me why it's happening to me and how can i solve it