My comments in red. 

M-Kate wrote:

I’ve agreed to see a marriage counselor with my husband to help me to accept that my husband is bisexual and to discuss our relationship.   You don't have to agree to accept anything. And it sounds like it's your bisexual husband who has the power to make you think that you have to.

I’m trying to understand why I’m still feeling so much anxiety.   It feels like my body is telling me that I’m not “safe”.   What does that mean?    I think that I’m afraid of being hurt again.   In addition, I’ve lost confidence.  I’m unsure of everything and I often feel panicky.   I thought that I knew my husband and I thought that he would never cheat on me. Your body is talking to you for a reason. Women have their own power. Intuition. Your body is telling you that you need to listen to it.

I understand that exploring his bisexuality is important to him.  He explained that his behavior had little to do with me and more about doing something for himself.  He acknowledged that he was being selfish and dishonorable when he cheated on me years ago and when he planned to hook up with a guy again just two months ago.  It must have been very important to him since he took significant risks.  I think that it scares me that since it was such a priority for him just two months ago, it could be a priority again in the future.   I think that if I stay in this marriage, I will need to accept that I could get hurt again.   I realize that people make mistakes, hurt each other, and can heal and move forward.   In addition, nothing would be guaranteed with someone new.   There is a lot of good in our marriage that is worth trying to save.  Blah blah blah....he explained....he acknowledged.....he cheated......he planned....he he he. He's even got you concentrating on him so much that you talk about him more than yourself. Why would you stay with a man you know may hurt you in the future? 
Yes there was a lot of good in my 38 year r'ship too, but I didn't leave because of all that. I left because I realised all that 'good' stuff was only the shine that covered up my loss of self-esteem.

However, I never thought that he would like a threesome and that he would be turned on to watch another man have sex with me and then have sex with him as well.   To be honest, I don’t know whether I can get past this one.  Again, it must have been important to him to suggest it to me.   I understand that it would be a way for him to explore his sexuality with me involved as well, but I’m surprised that he didn’t realize that suggesting this scenario would hurt my feelings and make me question his sanity.   I would like to try to understand my own feelings about this.   Why is the threesome suggestion specifically so hurtful?

• I’ve always thought of him as my “protector.”
• How could he truly love and cherish me if it would turn him on to watch another man have sex with me?
• He would be willing to put me in harm’s way & expose me to danger.
• He didn’t realize or care how I would feel when he suggested it.

I still feel angry about this.  I’d like to know whether he empathizes with my feelings on this specific point.   What did he expect my reaction would be?  Was his head so full of gay porn that he temporarily lost touch with reality?  Perhaps a marriage counselor will help with this conversation.

 I think that he is getting frustrated that I keep asking the same questions. He sometimes feels that I’m attacking him and judging him.  I think that I keep asking the same questions because I’m not able to accept the answers. He wants me to move forward, but I’m not sure that I feel confident that we are really on the same page. M-kate....I've reached the end of your post and can only say....we get so many new Forum members who seem so lost and confused but you first registered only this month and seem to be quite on to it, you know exactly what to say, when to say it. Like.....you've almost given the answer before you've asked the question.
 

E
 

My ex never suggested a threesome but if he had I would have felt like gagging.  And I would have left him earlier.  I would have been so distressed - why would he want to see another man having sex with me, that goes counter to my profoundest feelings.

Just to put this simply, your H is gay in denial, that means he's pretending he's not gay.  If you had a threesome, and I have read a firsthand account of one here, I think you would find that he is turned on by watching the man perform and you are not the person of interest for either of them.

Why would a straight man want to do a threesome any more than a straight woman does.  

I would not touch that marriage counsellor with a barge pole if I were you.  Find a counsellor for you - preferably one who doesn't have an lbg+ agenda.

And good for you, it is good to be angry about this, but it is also time to be wary and self protective - he is not the man you thought he was, he does not have the feelings you thought he did.  And it very much sounds like he is not so much a protector as entirely self interested.

Look after yourself.