How did you rush things too much? He agreed to open. You are not a mind reader. You can only go by the info given.
He was dating and sharing sex on his side already/first, so what's wrong with you
also exercising your option to date/share sex with other people?
I think that you help him to overcome this by encouraging him to work with a counselor and recognizing your own limits. You cannot be his counselor.
Maybe this will help him find someone:
Polyamory-Friendly Professionals Directory
www.polyfriendly.org
While waiting for an appointment, or to try several out to see which counselor "clicks" for him, he could read the
Jealousy Workbook by Labriola. She has some articles online too.
By Kathy Labriola, Counselor/Nurse JEALOUSY IN OPEN RELATIONSHIPS In my counseling practice, I work with many people who have chosen to have open relationships--to have more than one intimate sexual relationship. The biggest obstacle to creating successful and satisfying open relationships is
www.kathylabriola.com
Is it a fear of "I can't compete"? Like, he gets weird about men because he's got that same equipment, whereas with women, he doesn't even have the same equipment to compete with, so he doesn't stress?
Is it that he knows himself and how he thinks/feels because he lives inside his own body, so when he's the hinge with more than one partner he knows what's going on, but when YOU are the hinge he's not as sure, because he's never dealt with you as a hinge before?
Does stuff like this comes up?
COMMON PITFALLS IN OPEN RELATIONSHIPS Many people who are in a primary relationship stumble into an outside relationship either by choice or by chance, and once involved, things can go beautifully or can go terribly awry. Here are some of the most common problems that develop and some ideas for
www.kathylabriola.com
Is it about managing his own NRE and dealing in yours?
Is it grief? Like, even though this was a wanted change, the "new normal" isn't totally here yet, and things feel uncertain, and he's grieving the loss of the "old normal" because he know what that was and it felt more stable? He didn't expect to grieve?
Some of the stuff is his stuff/his responsibility. Some of it is your stuff/your responsibility only. Some of it is "our shared stuff/our shared responsibility." Be clear on which parts are which. It is NOT all "your stuff." It is NOT all "our stuff." Some of his personal work to do is just on him because only he can do it.
I want to be there for him and help him to get through these feelings, because he is really important for me. Do you have some advice how to handle a situation like this?
It's okay to be there for a partner in healthy, appropriate ways. It's another thing to "take over." Unasked for help is not helping. You could talk about what is and is not appropriate help, what are and are not reasonable and rational requests to make of you.
Like, you can't be his counselor. That's not appropriate.
You can give him a ride to the counselor and back, because a therapy session can leave one knackered and not up for driving. That could be appropriate help.
You could deal with getting groceries/making dinner so he doesn't have to do it and it frees up an hour for him to do online counseling in. That could be appropriate help.
Talk things out.
Galagirl