Anal Sex Exploring

My husband and I have recently ventured into anal sex. He says he actually enjoys it contrary to how he felt about it intially( I was the initiator). But I have yet to reach my enjoyment stage. We use lots of lubricate, we take it slow with less than 3 inches of insertion, I use relaxation techniques, and we do not cross contamination. I'm a beginner and need some advice from any mature veterans out there:

Why do I have the urge to poop during and after? --Although nothing is there---

Will I ever get to the point of enjoying it with hope's of a grand orgasm. If so, how?

Does anal eventually produce it's own lubricate or does it really solely on external lubricants?