Everyone has their own guidelines (personally - I believe 7 year olds should not shower with parents) but get professional input on this. If this ever came out at school, church, etc, CPS could be at your door. Is this child your oldest and setting the pattern for the younger kids? If not, what is the relationship between parents and other kids? What was the protocal? Basically, what are the dynamics within the household?
Counseling sounds like a good idea - but for both of you. One reason is parents need to be a team, not one being the bad guy. Second reason, children have nightmares and may want to sleep with their parents at times, but your husband can use direction in teaching your son it is okay and safe in his own bed - alone. Third, with a full time job, 4 kids and a husband that gives little help - you need a sounding board and learn to release a little stress. Lastly, you may be extra sensitive to some situations, but it sounds like your husband could learn boundaries and teaching those to the kids. If he won't go, go alone.
Good luck, I wish you the best.