I just want to say that it is okay to express to them if you feel jealous about the many conversations they have with each other that you don't get to take part in. You don't have to frame that as an accusation, it's just a chance to share how you feel. This is hard for you, but you are trying. It's not all bad for them to know that.
I hope that you get feeling better, and that you have a positive and productive sit-down.
Love means never having to say, "Put down that meat cleaver!"