The happyiest ive ever been, yet im sacred and anxious.. I feel desperate.

Im listening to music.. and while i do i feel like me .. it is possible to be the happiest ive ever been but at the same time to be desperate, scared and terribly anxious.. I feel bad.. that feeling like this is a betrayal of my husband who is the best thing that has ever happened to me.  But its not enough to make me ok.  Im afriad that im my mask is gonna slip anyday now and somthing is going to snap.. Im getting fatter and dispite all thses neg feelings it not enough to get me up in the morning jogging and doing something about it .. whats wrong with  me... !