He's going...

I do not have any really good advice, but I understand and can only offer my perspective on this.  It sounds like he is indeed insecure and is manipulating you- or trying to - so he can maintain control over you or the relationship. My guess is that he is afraid you will leave and is trying to test you by giving you an out and seeing if you'd take it.  Again- maybe I am wrong here- I know men are less complicated than women , so I may be making this more complicated than it sounds. Honestly, I am trying to figure it all out myself.
One thing I am sure of is that allowing someone to manipulate you or control you in a relationship keeps the dysfunction alive and well. I am totally committed to my marriage and yet if my husband pulled this funny business, I'd have to call him on it. I'd tell him that he can believe me or not, but that my love, committment and faithfulness are solid and sure and that the problem is his, not mine.  I would not for a second let his threats or fit pitching  cause me to be someone I am not or behave in a way  just to soothe his jealous tendencies. Of course, I think it is good to remember to praise him for that which is truely good and to remind him of your love for him, but he is a grown up and should deal with his insecurities.  Unless he is not really committed to you and just wants an out  and is using this as an excuse, I believe he will come around  to have confidence once again.

I hope this rambling makes sense and helps you a little.
-Renee
(VSGis4me)