I don't see your husband's request to not see your bf while his mother is in town as unreasonable. Why was this even an issue with you and your bf, it just seems like common courtesy to me, it's only a week? I imagine your husband seeing you resistance to this request as a sign that things are going to return to how things were and a rejection of his needs.
It definitely sounds like he has some needs that aren't being met. Do you go out with dates with your husband or is that just reserved for the bf and the husband just gets boring home stuff? Sit down with your husband and have some serious talks about HIS needs. Work out a new schedule, based on the current situation (this may have to change each month). As I read it, you expect the time with bf to stay the same and it's your husband that must make all the sacrifices when school, work, family or anything else gets in the way - that's extremely selfish on you and your bf's part.