threesome

My boyfriend and I been together for 8 months now and when we first started talking we've talked about one day having a threesome; I'm a very jealous girl this is my first real boyfriend so I'm very overprotective And I get jealous over any small thing; but could days ago we were talking about it and we had made up a lot of rules getting prepared but I'm having doubts I wanna wait after couple more months maybe years but he feels like if we continue with the plan then that'll make him and I closer as partners I hope so but I'm just scared; I've done somethings with a female before but I don't think I want to sexually "share" my boyfriend with anyone; I want to make him happy but yet i don't want to put myself in a uncomfortable situation just to make him happy; I'm afraid after its over with I might feel worthless; I just really need to read other stories and experience 😩 please lmk