grlnxtdr
Glad to hear you decided to go to counseling given the difficulty you were having in attempting to have the conversations by yourself. It appears you did not say much to your husband but he probably knows what the issues you want to discuss with the therapist are.
You got married quite young (21 I believe) but the posts do not indicate if the great difficulties that caused you to get to this point have anything to do with the current situation or not. You might be feeling what you are feeling partially because you have girlfriends your age who are dating and going out and you have the restriction of being married at present, and still being so young feel you have missed something. That would be understandable
I would caution you on one thing however. Just from your post, it appears you are determined to put everything on the table, which you certainly should do since you now are going to be paying someone for help, but I think you should realize that unless your husband totally changes what his feelings are he will probably see this as just another demand. Your therapist will obviously try to present this to both parties in the best possible light.
It is very difficult for non monogamy to work in any form if one of the parties remains steadfastly against it. Unless your husband changes his views, which from what you have said, seems unlikely, it is going to be a hard road ahead, therapy or no therapy.
I still just think you married too young, and need to have freedom. Unfortunately, not a large percentage of men, or women for that matter, will agree to share their partners intimately with others. That is just a fact of life, fair or not fair.
Good luck with the therapy.