It seems that the lack of desire to have sex that you are having may most likely be a result of you the pain you are having during intercourse (also known as dyspareunia) . And what you are describing as feeling as though your husband is "caught on something" and the cramping you are having seems to be what is known as vaginismus. Both dypareunia and vaginismus can coexist. They can follow traumatic vaginal deliveries. They can also be due to vaginal yeast infections, urinary tract infections or more commonly psychological factors such as anxiety and stress. Nonetheless i would advice you to get a thorough gynecological check up. If the check up is normal then mostly likely the cause may be psychological, in which case you should talk it out with you gynecologist. There surely is a solution. Don't be worried. Having earlier been able to have proper intercourse with your husband, is a very good predictor that you surely will continue to do so in the future.