It is unfortunate that your heart is already taken by this man. Your path choices will hurt which ever way you choose to go.
If you had only just met him and came here for advice, I would say run run run. Plenty of fish in the sea and all that.
You are not a JW. The elders have no say over you or control of you.
You should continue to research this religion as much as you can. Share what you find with your boyfriend. It is NOT a harmless, loving religion. It IS a mind control cult.
He started this relationship with you in contravention of the rules of the cult. The burden is his not yours.
Make no mistake, if you want to continue to see him, you will be expected to convert.
Choose wisely.