I am sorry you are hurting.
You do not state what you need in specifics. You only say "please talk to me!" so I will talk. I see you. I see your pain. I will also say this -- "don't take on extra baggage! Reduce your own stress!"
YES. It sucks! Breaking up is going to suck for a time. It is the Time of Suckage. *hug*
I can only share my limited perspective on this situation. Here is what I see. I do not know if it will help you.
If B & J have a personal limit of only dating couples? It is not YOU preventing G dating J. It is THEIR couple limit. Is G shooshing his disappointment on you inappropriately? If so, it is NOT YOU who has imposed the limit. If G wants to date J, G must tell J this. Is G doing it? If you are doing it for G because of fear of G blaming you?
G is out of line not wanting to do G's own work directly. You could learn to say "No. I will not do your work for you."
If J wants to date G, it is on J tell G this. Then to renegotiate that couple limit with B. Still not your baggage to hold. It is J's job to do. Are you doing it for J? How come? You could learn to say to J "I will not do your work for you. Approach G direct."
If B has a grievance about your "dramatics" -- well, B is not wanting to talk. You cannot get the verify right now. Is it possible B means "you do not give people emotional space to do their work in? You take things on your plate that are not your baggage to hold?"
Do not do serious relationship maintaining work by cel phone text. Most of what communication does is not oral or written -- it's the paraverbal. You miss a huge chunk of the party if you do not get this part. That IS some of your baggage to hold here in conflict resolution within this polyship. You choose to engage in the texting arena. You could choose to not text. You could choose tell the person texting you "This is serious relationship convo. I cannot text this. Please make phone appointment (ok choice) or face time appointment. (best)"
b said they are fed up with my dramatics, on sunday we had a day out and I got upset because we didn't spend the day together and I was left outside most places to look after the kids (mine and g's) while they went shopping
Why are you and G not arranging for a babysitter? So you can go out as 2 adult couples then? It is not B & J's problem to arrange your babysitter for you.
If a couple date is desired and no sitter is found, why are B & J not informed of the realities of child management? "Well, guys, if you want to go out we are up for it. But it has to be family friendly style cuz we have the kids along. You know what that means, right? You still game?"
If they are not parents themselves they may not know
what it means or see when/how they are being clueless. This is on BOTH you and G to alert them to the reality of life with children. Couples can do family dates but they need to know what it is to hang out en famille.
Is G shooshing the whole childcare job on you? When are you allowed fun on these couple dates then? Since the couple will only see you as a couple. (Their limit.) If the kids have a need to be watched carefully on couple dates,the parents must do this for their offspring. What is the co-parent G's responsiveness to this need? You are willing to do your share of the kid watching. Is G willing to do G's share of the kid watching?
we have tried ringing, we have been texting as it is the only way as j's partner said they don't want anything to do with us anymore so texting is the only way we can talk (with J?) at least till we can try and get together as a group (if/when B is willing to talk?).
This is adding to your stressy. Not taking away from it. You have pretty much said all there is to say -- that you are willing to sort things out.
You could back off now. You did your bit. Wait. (Vent here if you have to in the waiting time rather than texting vent stuff over there cloduing the issues. Do not ADD to the problem. Could strive to take away from the problem.)
Since you are willing to back off and have J & G date without you? Why are you not willing to back off and let G sort this business out with J? Let G own their emotional baggage instead of doing the work for G?
Let it be what it will be. It's hard to FEEL. But it is VERY easy to do. Just decide to keep your nose clean and do all you could do in this case. Have you done it? Yup. Now stand back and wait and see.
Why are you not willing to let it be right now? What is your need not going met so that you CAN be willing to let it be right now and wait patiently?
Hang in there!