My impression is that you need to return to your psychiatrist and see if there are additional medication changes that might help you.

That terrible overwhelming sense of guilt is a sign of depression and possibly delusional thinking.The anxiety may be a bipolar symptom or it may be a separate anxiety disorder but clearly the clonazepam you are taking is not working well. My guess is that the anxiety is actually a bipolar symptom but you will have to talk that over with your doctor.

The physical symptoms you are describing of anxiety can be helped with deep breathing, mindfulness techniques, a gratitude list is always helpful. You must force yourself to focus on other things and not blow things like that dream way out of proportion. It was just a dream, that's all.

The reality is that
+your husband has not left you
+he wants to work on the marriage not leave it
+your behavior did not include physically cheating which will make it easier for both of you to heal
+you were sick when you did these things and have to accept that fact
+you are still sick and cannot trust your mind to perceive things accurately or tell you the truth about what's going on around you and about what is best for you
+you need to seek out people you can trust to help you stay focused on reality until you get better

If you do not have a counselor you really, really need to get one for yourself. That person can help you a lot more than someone on a chat forum. Be sure and ask for someone who can teach relaxation techniques or has experience with anxiety and bipolar disorders.

I hope you feel better soon.

Best wishes