Welcome to our forum.
You have several relationships that need time and tending to among the adults in this triad:
- each of the three of you individually -- "you time"
- you and husband
- you and girlfriend
- husband and girlfriend
- all three of you together -- "group time"
If any of those areas are getting neglected, then there will be fractures in the relationships and hard feelings. Please sit-down (all three of you) and figure out how you can spend quality time for each dyad.
One other thing would be to write up lists of your wants and needs. Then, have a sit-down where you share those lists with each other, and try to work as a team to get everyone's needs met as much as possible.
Sometimes things get easier over time. You will probably need a lot of patience to even attempt to save this. Also, try to learn to be a better listener, even if husband and girlfriend don't follow your good example. You need a better understanding of what's driving their behavior.
I wish you well, and hope Polyamory.com can help.