coco..is there a reason that your husband is not attractive to you? does he have bad hygiene? does he not show you attention outside of the bedroom?
The other guy is a fantasy. PERIOD. He may have been someone you found attractive..but he may not have all the other qualities that your dear husband has.
You say he is a lovely man. If he is a loving man too, then maybe you can sit him down and tell him your libido is lowering (no need to crush him with the fact you found someone else attractive) and tell him you need to work on things to make it a bit more exciting for you.
Look at one thing each day about your husband and think about it. does he have beautiful eyes? fixate on that..nice bum? even better

anyway fixate on ONE thing positive about your husband a day..I promise in a few weeks..you will be WAY more attracted to him!!!