Hate nick name

We named my son Jerome. Gave my husband a list of names that meant the same that i liked and he chose which he liked best. Before i knew it, the moment name was announced, my sister in law was calling him JJ, I hated the nickname. And before long, my husband was calling him Jj, i just dont like the double letter or any letter at all. Jay would be fine because it can be a name but jj? My name is Mimi but would someone call me M? Sounds so lame to me. Worst part is i naturally call people by what someone calls them. i feel people wouldnt know who am refering to if i dont call the person by what they call them. So i find myself calling my son JJ when around the dad and i hate it. Have told my husband i hate that nickname. But dont want to be the one to tell my SIL. I loved the name but they are just spoiling it for me. My reservation to not complain much is because i dont want to come off uptight.